A lot of these comments are vilifying you for being asshole, but u/dethsremorse is the one you should be listening to. You are not responsible for fixing your girlfriend, nor should you try. It is perfectly OK to think that she has more going on than you can or want to handle. It is absolutely natural to want to be with someone who is emotionally and mentally stable, and frankly, it sounds like your girlfriend isn’t, through no fault of her own. Even if you love her, if you don’t have the patience or desire to help her work through her problems, it’s OK to end the relationship. You might feel like an asshole, but you’re not doing your girlfriend any favors by sticking around and being unempathetic to her problems. There’s nothing wrong with moving on with your life and letting her move on with her life which ever way she can. You could gently recommend that she go to a therapist who can help her work out her trauma, but you aren’t that therapist and it is fair if you don’t want to take on someone else’s major issues.

It sounds like maybe you should just stop fucking around with substances you don’t handle well altogether.