My boyfriend is psycho?

So my boyfriend in my opinion is great and we are perfect for each other but I'm convinced he needs some help and that there's some aspects about him that can contribute to a very unhealthy relationship. For example he tried to commit suicide several times before and there's scars all over him as a souveneir. He says that I'm the only reason he hasn't done it again which is sweet but scary.... Also he takes things to personally. He has a slight social problem and he dosent really have lots of friends to start out with and yet they keep leavin him for the smallest reasons and he cries and takes it to heart and claims no one but me will ever understand him. Also he has a past where his mother just left him and his older sister for her fianc� and he never really knew his father. For a teen he sure has gone through a lot of heartbreak already in his life... And I don't want to contribute to anymore so I'm convinced I will nver ever leave him... But the thing is he is very moody and he self inflicts the tiniest things how can I convince him to stop doing things like that? Or at least breaking the habit.