Breaking up😐

I really kinda want to break up with my bf... he does a lot of things I do not like. He does drugs.. sometimes he just act crazy and stuff. And I find it so hard to leave him because we have a child. She's not the only reason why we together but it's just harder when there's a cuke involved. Everytime I say it's over he does something that makes me forget about it and I don't want to waste my time anymore. ANY TIPS!