\[Content warning: if you are currently in a paranoid state then I do not recommend you read this.\]

I am a borderline in recovery. There's a man in my friend group. I was always cordial to him - of course I'd be - but I never felt an attachment toward him. I guess he interpreted my cordiality as an invitation for friendship, and he ramped up the emotional intensity of our relationship from 0 to 100 in an extremely small amount of time. (I know that's a borderline thing; I've had it happen to me.) We were barely friends, at least in my opinion, before he was calling me in crisis. He confessed to being borderline and I, in an attempt to comfort him, confessed as well. Because of this, I've become his go-to friend when he needs support, and to be totally honest, I hate it. I'm struggling and I can't be an on-call therapist for him, but I've yet to be honest about my needs because I know it's going to trigger him. Our relationship basically revolves around him and his needs. It started with him in crisis and it's been a series of crises since, and I can't find it in me to be frank with him when he's struggling and needs my support. I'm beginning to resent him even though I know it's unfair of me, especially because I haven't been honest with him. 

On the weekend he confessed that he loves me and I'm his FP. This...is terrifying, to be totally honest. He's said that no one loves him as intensely as he loves them, and he loves me intensely, and I don't love him in return. I don't feel as if he actually loves me, though, I feel as if he loves what I do for him. He loves that I'll drop everything to be there for him even if I'm sacrificing myself. &amp; it's painful to know that I'm confirming his anxieties and his trauma. I am the friend that every borderline is terrified of - the secretly-resentful friend. He's totally and wholly reliant on me for emotional validation, and I can't do that for him. I can't be enough for him, and I know he's going to inevitably split on me. &amp; it's my fault, because I didn't communicate with him early enough and his expectations of me are so high that they'll inevitably be betrayed. I am an autistic introvert and I don't possess the social capacity to hang out for hours at a time, but when I say I need to leave he'll sadly say "please don't abandon me" and I'll feel obliged to stay. His emotional reality is his emotional reality, and I know he's not trying to manipulate me. Being borderline myself, I know that when you feel abandoned, it's a crisis. It's a reality. I can't ethically walk away from someone in crisis, even though I know I'm not responsible for managing his emotions. But being around him exhausts me. He isn't a positive presence in my life. He idolizes me and it's terrifying. &amp; I feel horrible about it. I'm conflicted, I'm scared, and despite the self-awareness I feel as if I'm watching a car crash in inevitable slo-mo and I'm doing nothing to stop it. I know I'm not totally to blame, but he isn't either. He can't help it. He's started group therapy, but recovery isn't a quick process - believe me, I know. But I'm not equipped to handle his highly intense emotional dependency. I desperately need to talk to him, but I'm terrified I'm going to trigger him into a suicidal episode. He was hospitalized last summer and he's confessed to me that he's beginning to slip again. I feel as if because I didn't establish boundaries early in our relationship, doing so now would be interpreted as a betrayal from him. He'd resent me for deceiving him, and I wouldn't fault him for it. I've betrayed his trust, I've deceived him, and I don't know what to do.