Sam and anger in S8 is an interesting topic to me. Because the thing is…Sam is REALLY REALLY REALLY angry at Dean. And he is trying to be fair and reasonable and all that crap (particularly about Benny), and he is failing miserably…because he is so angry.
Sam’s anger is mixed up with a lot of guilt, too. The problem with a situation like this, when there is no simple right or wrong, when both parties have behaved badly, is that it’s hard to unweave. You need some distance, which Sam is unable to get at this point in time. I mean technically, yes, Sam could leave Dean. But I think there are a lot of reasons why that would be very difficult for him at this stage. And I don’t think Sam realizes how much he needs that distance. He wants to be normal to get away from hunting - not to get away from Dean. At least, not consciously.
Some of Sam's anger is about old stuff, from long ago. Some is recent. The reality is, back in S4 Dean did tell Sam he was a monster, that if he didn’t know him he would want to hunt him. I know, you can pull plenty of compassionate quotes from Dean from the same time period and before, but “You’re a monster” and “if I didn’t love you I’d kill you,” are statements that can’t be much improved by context. After Ruby betrayed him, Sam basically gave up that anger. And the reality is, he had lied to Dean and strangled Dean etc., etc. So it’s not like Sam was an INNOCENT VICTIM or anything. But still, the way Dean handled Sam’s powers, by the end of S4 (I do think Dean was really trying in the first two seasons, although he wasn’t able to completely hide the fact that he was disturbed by Sam’s powers and thought that they made Sam a “supernatural freak”), was very difficult for Sam. Remember, Sam sees his powers, the demon blood, as a part of himself. While I think it’s incredibly unfair to blame all of Sam’s demon blood-related shame on Dean (Sam is, actually, his own person, and his opinions influence Dean just as Dean’s influence his), Dean was pretty damn rejecting about the whole thing. It was one of many factors in the appeal of Ruby.
I think there was some really deep pain there, on Sam’s part, that was never addressed. Sam stopped drinking demon blood and they forgot about it. It’s probably not a coincidence that S8 is also the season where Sam reveals that he believes he can be cleansed from the demon blood.
So Sam has all these buried feelings about his own monsterousness.
More recently, Dean has been putting down and verbally harassing and guilt-tripping Sam about his decision to quit hunting for a year (as if Dean had never quit hunting for a year) and the fact that he hadn’t looked for Dean. Sam is PISSED about this. He makes that very clear. Dean has come back, and Dean has come back nasty.
And yes, we and Sam know that Dean has been through hell. Okay, Purgatory. Well, Hell, too, but that was a long time ago. But no matter what Sam understands intellectually, it doesn’t ease the pain of what is actually happening.
And then it turns out that Dean has become BFF with a vampire.
On the other hand, Sam feels guilt, too. Sam did, actually, lie to Dean and strangle Dean and accidentally start the apocalypse. Sam, while soulless, smiled while watching Dean get vamped, and killed a woman that some guy was trying to use as a hostage. Just because she was inconvenient. This stuff happened. Sam did take a whole year off of hunting. And probably, people died - this isn't Sam's fault, but it doesn't change what it is.
Sam didn’t look for Dean. And say what you want about Sam’s motives, about what his obligations were, about what he believed, but this is Sam here. Sam who believes that his love for his brother is one of the best parts of himself. Sam who already feels guilty about how his brother has suffered because of him, for him. “I owe him this. I owe him everything.” “I mean, you sacrifice everything for me.” So yeah, Sam may be trying to suppress it, but he feels terrible.
Sam has a bizarre combination of anger and guilt, both directed at the world in general and Dean in particular. And Sam’s not really processing it, or able to process it. Because of Dean’s hostility and guilt-tripping, he can’t have an open conversation with Dean about it.
And then there’s Benny, and it’s simple. Everything that’s wrong is about Benny. Benny becomes the problem. And that’s headed towards disaster.
And the anger and guilt feed into each other. Dean heavily implies to Sam that he trusts Benny and not Sam, and Sam feels like the horrible demon-blooded monster who is worse than a vampire who killed god-knows-how-many people, and then he feels angry at Dean for making him feel that guilty, for saying something that really is totally unfair, and guilty that he feels so angry, and angry that he feels so guilty…
And so you get Sam’s confused combination of guilt and accusation in Sacrifice. Sam just can’t see it, can’t separate his accurate guilt from his righteous anger. Can’t separate his realistic guilt from his fear of being the bad brother, the brother who betrays his brother and lets him down and is just -
Dean’s opinion of him becomes a sweeping condemnation and being good is about convincing Dean that he’s good but he’s pissed off enough to recognize that Dean doesn’t actually know jack and is just being an asshole for his own reasons and yet here are all this undeniable examples, undeniable proof that Sam is a terrible person, a terrible brother, and Sam doesn’t want to die, not really, he just wants it to stop. Letting Dean down is the worst thing he could ever do, so painful and terrible that he’d rather die than let it happen again. But he is so. fucking. angry the Dean is being such a hypocritical asshole. You’re an asshole but I deserve it no, wait, I don’t, no wait, how could I even think that I don’t I’m so horrible, and you’re not an asshole you’re a better brother than I could even begin to deserve, no wait, maybe I kind of don’t deserve your condemnation, I’m bad but maybe not as bad as you think AND I’M SO FUCKING ANGRY!
It's not that verbal a thought process, I don't think. Just a mass of seething, voiceless emotions that Sam is struggling to keep tamped down.
So Sam falls apart. In Sacrifice, he's still doing the thing where he makes puppy dog eyes and asks for reassurance. He wants Dean to tell him that he’s a good brother and good person…but as I may or may not have said, I don’t think Sam ever fully believes these reassurances. Certainly not for long. He asks for them and asks for them but they never give him the peace of mind that he craves.
And Dean is really the worst person to have this conversation with. Given that Sam’s feelings of guilt and anger are so deeply intertwined with Dean and their history, having this conversation with just about anyone else alive - or maybe even dead - would be better. But the reality is, Sam isn’t much of a confider. And the person he’s probably the most open with is his brother. Certainly at this point, when he has no one.
When Dean in Sacrifice doesn’t want him to die, it’s not…Sam is going to see it in terms of Dean just feeling that way because he loves Sam, because this is how he always is about Sam. Where Sam is concerned, Dean, unlike souled Spike from Buffy, cannot say, “It has nothing to do with me." Sam gets a reaffirmation of love, but whatever Dean’s intentions, it's also a reaffirmation of guilt. “Look at all these wonderful things I do for you” is not, actually, a very good message for someone who feels like a terrible brother and a worthless person. And yet, part of the problem here is that Sam is resting his whole self-worth on Dean’s opinion. Dean obviously can’t, in the moment, solve the deeper problem of Sam resting too much of his self-worth on Dean, so isn't using that problem of Sam's to stop Sam from ending his own life a good thing? (Assuming the goal is to stop Sam from sacrificing himself.)
The situation is very complex. It’s not a matter of Sam doubting the Dean loves him. It’s more a point of doubting that Dean forgives him. That Dean trusts him. And it is complicated because you are not necessarily entitled to another person’s forgiveness and trust, but we also see earlier in the season Dean coming down on Sam for wanting to leave him…so you’re not going to forgive him, or trust him, but you’re going to try to insist that he be with you?
And, again, that’s not the way to ask for forgiveness. Falling apart and talking about how much it hurts when your brother…Chooses an angel and a vampire over you? Turns to an angel and vampire instead of you? Trusts an angel and a vampire over you? I’m struggling for the right way of putting this. Whatever the situation, Sam falling apart is not the best way to handle it.
But the reality is, there were lots and lots of reasons why Sam and Dean were unable to have this conversation, calmly and reasonably, at a better time. And not all of them are Sam’s fault.
What Sam wants to hear is not “Look how much I love you!” After all, that’s what Dean basically said in Metamorphosis, when he told Sam he’d want to hunt him if he didn’t know him. Dean also made his affection quite clear in When the Levee Breaks right before calling Sam a monster. A reassurance of love is just reminder of what Sam already knows - it's not a reassurance that Sam wants to hear.