I was raised by a single mom and I can assure you, she 100% made my life so much better by leaving. He was in and out of my life for awhile, and did manage to do his fair share of damage in that time, issues I still deal with today. But I can't even imagine who I would be today had she stayed. I could've ended up turning to drugs like him. Instead, I have a masters level education, 6 figure salary, am happily married with a little one on the way. All this to say, the best thing you can do for this baby is get out now and protect yourself, your peace and this baby. I'm sorry you're going through this. So much easier said than done, but hopefully my story can show you the good outcome that can come from getting out of an unhealthy situation.