I am sorry about everything that you are going through. You seam like a very strong and logical person. You are right to have your hesitations about getting back with your husband and I understand he has to gain your trust. If you consider giving him another chance you will need to go on couples therapy before you even think about giving him a chance. When you are ready to attend couples therapy talk to him a bout healing your relationship be going to couples therapy. Explain to him that this will not automatically mean that you are going back to him but you want to work on the broken relationship and see if there is a chance for healing and forgiving. It looks to me like you husband has so many things to work through. He will need to have make many changes before he is even ready to try to build a relationship with you again. From your side you will have to learn how to forgive him and I know that is not easy but it will free you from a lot of pain. So I think having the talk with him about seeing a couples therapist if he think he has changed enough learned his lesson and is willing to give your relationship a chance. You also will have to be willing to heal and let go of the past and move be on the pain. I suggest the book relationship Rescue by DR Phil and forgiving for good.
Let me know if you have any other questions