I am so very sorry you are going through all this pain but sadly, it's a common tale and when addicts are active in their disease nobody is safe around them. You have experienced only a taste of how bad it can be, please take the lesson and leave the relationship behind, girl. This is no life for you and your child.
There are a million reasons why you need to be done with this, one is that when you had drugs at your house YOU could have been arrested, charged and your child taken away. It's happened before here and is heart breaking.
It won't be easy, but resisting the urge to contact him or take calls from him is the best way to cut ties. He isn't the person you thought he was, the person you see now is what addiction has turned him into.
The "woulda's, coulda's, shoulda's and what if's" only make it more painful. It's not your fault, you can't make him stop, and nothing you do or don't do will change what is happening.
Please save yourself and your child while you can.
Hugs