Feeling Used by Friends Who Remind Me of My Abuser

I'm finding more and more that I don't think I like a couple friends of mine, just because they remind me of the house we used to live in together with our abuser, and because I don't think they were entirely innocent? Rant ensuing below. TW: discussions of my trauma My abuser was diagnosed with BPD, and was refusing to get treatment. At the time I tried to do as much research as I could on this to support them. Their partner at the time, however, didn't and kept doing all the usual unhelpful stuff: saying their emotions were invalid or disproportionate, telling them that they were overreacting, saying they weren't making any sense, etc. His friend, our other roommate, kept saying that they (BPD roommate) were crazy and demanding and abusive. Eventually they broke up with him, very shortly after an attempt. Being in the middle of all this, I know they were doing manipulative things like threatening su*c*de or blaming us for triggers/bad days. They would scream at their boyfriend over anything, like he couldn't do anything right, even if he had tried, and then refuse to communicate what they needed instead. It was a terrible experience, and I excused a lot of it because I knew they had BPD and PTSD and needed a friend. I really, really cared about them and wanted them to be happy and feel safe. The last straw for me was when I learned they had SA'd me multiple times when I was unconscious, and that they were saying bad things about me behind my back: I wasn't a good enough friend, I was too pissy most times and people pretended to like me, and that I frequently abandoned them. I'd lost my job because I couldn't go to work several times after staying up with them all night. I took them to the hospital after their attempt and waited with them in the ER for 3+ hours. I reminded them to take their meds and would watch them to make sure they were being safe. I went on mini adventures with them when they needed out of the house. And I wasn't good enough? Abandoning them? I genuinely don't know what else I could've done. For that reason, I know how their boyfriend felt. However, he certainly didn't try as hard and was much more invalidating. Now, talking to him on occasion, I think he's refused to take responsibility for a lot of bad he's done. Same with his friend. They act like they're the victims in the situation, but have learned nothing. They're still invalidating and disrespectful and violate people's boundaries regularly. I dunno. I'm just so tired of feeling used by people, and realizing that trusting certain people was a mistake. I don't talk to those friends as often, and I don't trust them to validate my own emotions, but it really sucks.