Ah, honey. This is so hard. You absolutely can not have a good or normal relationship with someone that is currently addicted to something (drugs, alcohol, sex, etc.). The reason is that they are sick. They put their drug of choice over and above everything else. They will lie, cheat and steal to feed their addiction.
This is painful. But living with an active addict is not healthy. I would go to Al Anon. I would move to someplace where he isn't (parents, a friend or on your own if you can afford it) and tell him that you WANT desperately to be with him but he has to be clean. Get clean, and you will be back.
If you can't do that, then you must consider yourself codependent. And again, Al Anon will help. they'll teach how to set safe boundaries. Because it just can't ever be normal until he gets clean. And often, people around an addict know they need to get clean long before the addict admits it. It often takes bad things to happen to get through to the addict. YOU HAVE TO PROTECT YOURSELF!
Did you go to school? If you didn't, please consider college or trade school so that you can get a good job yourself to support yourself in the event that you have to. Not having income is probably the number one reason many women stay in bad situations. If you choose to stay with him now --- set yourself up for a back up plan by getting educated so that you CAN support yourself and your child if you need to. Paralegal, for example, doesn't take that long, isn't that expensive and pays pretty well once done with school. But really, anything you want to do, pursue it now.
I am here to chat with you any time hon. hugs