Well I think it's appropriate to share your feelings here, it's a safe place with people who understand.
I am sorry you are going through this pain, and think it is very wise that you decided to cut ties completely. Doing so will hurt for a while, but you will heal with time. Staying will continue the pain, and quite frankly bring you even more.
You now have a baby to consider and keeping this child in a healthy and safe environment is the most important decision of all. My prayers go out for both of you. It WILL get better over time, I promise. Please stay safe and keep your child as far from addiction as possible.
Hugs