in regard to what you are responsible to your H for and your vows? I disagree, you are supposed to stay in sickness and in health, unless you are being placed at risk. You are.
You are being emotionally and physically abused here. You have unknowingly exposed to god only knows what. That is abuse.
Addiction is a thing that you can't fix, only the addict can. When you walk away if he decides you are worth it, and starts the hard work of healing himself and dealing with his addiction, then you can decide if you want him back in your life. But please protect yourself and your child.