I'm looking for this fic but I don't remember the title or the author are, I hope you can help me find it. And oh, it's bottom!Dean.
In the fic, Sam and Dean (though brothers) become lovers recently, but something happen and Sam woke up with amnesia, didn't remember anything at all, even his own name. When he saw Dean, he instantly got weird and horrible feelings and it hurt him. Because these feelings, he thinks he actually hate Dean, and didn't believe at all when someone (I think it's the doctor) introduce Dean as his brother. And so begin their new life that full of hurting and sadness (on Dean's part). Dean didn't tell Sam that they're also lovers, and no one knows that they're lovers. But someday, he got revelation from someone (I think it's Catiel) and he recognize that the feelings he have around Dean is love, but not love for a brother but for a lover. He got confused and insecure, because he know that Dean loves Sam (as brother) but he didn't know if Dean love him now. He then talk to Dean about his amnesia and if Dean want Sam's memories back. After pressured, Dean admitted that he wanted Sam's memories to come back, and Sam got jelaous of the old Sam and felt hurt because he think that Dean wanted them become just brothers and Sam didn't want Deam become his brother but his lover. And cue the love confession with bitterment and possessiveness and obsessiveness, followed by Sam raped Dean. After that Dean said that Sam didn't have to do that, that they're already lovers. Because his shock, Sam got his memories back and blamed himself and fell into despair (I don't remember the continuation, though I think the fic got happy ending).