I'm glad you got all that out. My ex was/is an active crack-dealing, meth smoking drug addict. Our son is 5. I use the word "our" very loosely.
I had to draw the line when it came to the kind of people I would let be around my son. I want my son growing up in a stable environment that gives him every opportunity for success. That totally precludes being around drug addicts. Therefore his "daddy" is no longer allowed in his life.
Crazy, suicidal drug addicts do not make good fathers. Just because they are capable of making babies doesn't mean they should be around children. Your son only has you to protect him... your "boyfriend" is too busy being a selfish drug addict to truly care right now.
Walk away and stay away... and eventually you'll see by his actions what is more important to him - his drugs.... or his child.