This is an overwhelming situation for any professional to deal with, much less a girlfriend. This is not someone you can help — but someone you need to protect yourself from. For many years, I’ve dealt with men like your boyfriend and their girlfriend. It is a similar story each time. You think you are going to be the one to help him, and then you end up being yet another victim.
You need support for the process of untangling. You are doing more work than he is on changing him. It isn’t something you will be able to do. Let others manage him, while you manage your life and protect yourself.