My friend Peter and I disagree on a lot of things.  Most of the time, I feel inclined to 'agree to disagree' and leave it at that.  However, sometimes Peter is just plain wrong.  For example, recently, he posted on social media something nasty about a group of people in the mall.  He basically judged a group of 4-5 girls who were walking around the mall and shopping, saying things like, "Those smug hos," and posted a picture of them.  He was upset because the girls didn't donate to a charity in the mall asking for handouts, and then when he tried to tell them to donate, they laughed, cussed him out, and walked off.  One of the girls was my cousin.  I asked her about meeting Peter, and she said that he had followed them around the mall for over an hour but never talked to her or her friends.  She also said there was no charity at the mall, but a group of people asking for donations to go on a trip to protest something, and she and her friends wanted no part of it. When I confronted him about this, he started calling me a liar and accusing me of intentionally hurting his feelings by dismissing his perception of events.

Peter does this frequently.  Whenever something goes wrong in his life, he is automatically the victim and cannot be held responsible for anything that happens.  There's always an excuse.  He blames his depression for everything, including losing his job.  He lost his job because he was rarely on time and often didn't get his work done (which, coincidentally, was always left incomplete for reasons that had nothing to do with him playing video games excessively or spending too much time out with his girlfriends.) Right now, I am to blame for things going wrong in his life because I lied about what happened at the mall.  This has been his narrative for three weeks now.  His girlfriend broke up with him during this time (because he was cheating on her...  Which in his mind is her fault because of the distance between them), and I was to blame because he went suicidal and I wasn't there to comfort him (he essentially wanted me to act as a rebound and be a one-night stand to heal up his ego.  No, I don't do those, and he knows this.)  He also repeatedly pours his heart out to me and ends his rants with, "But how can I trust you since you hurt me when I was being vulnerable?"  I've refused to apologize.  This was my COUSIN he lied about, after all.  I don't owe him anything for his own lies. 

I feel like the answer to resolving this friendship issue is to just cut him off, but he can't handle that and I don't want to ultimately feel responsible for his death, should he decide to commit suicide.  As much as I know it's his own choice, I know I'll still feel somewhat guilty.  I also know I can't handle being the source of everything wrong in his life and having to apologize for doing nothing wrong.  I do care about this person, but I feel like it's just way too much at this point.  Is there some way I can loosely maintain contact with this guy just in case he really does need me for something, easing my guilt and assuring me of no concrete part of his future?