@AZ79, I feel for you. I understand your feelings on trauma contributing to illness. I do think that my breast cancer resulted from long term stress and trauma. I have done alot of emotional work as a result of my bc but I have a very supportive husband that I have been married to for 10yrs.
My first husband was abusive emotionally and I am so glad I left him with our son too. It's a long story of over 30 yrs ago but when I married that man I lost myself. I equated that marriage to drowning and when I left i thrived and built a great life for me and my son. Neither of us saw him ever again.
I know you say you can't just pack up and leave but if abuse is making you sick or killing you then leaving is a better option i think. There is so much support out there and if leaving is what want really then you should talk to someone about it.
Counselling is a really good idea it would be good to have a counsellor who had worked with cancer patients and also abuse.
You might be interested in a couple of books: Gabot Mate When the body says no and also Patrea King Your life matters. Great reads with a few natural tips to help. Best wishes