Well I have to add my 2 cents worth here. I applaud the fact that you have been honest with your husband about your liasons. I seriously think you need a therapist to find the deep seeded root of why you continue to put your health, your husbands health and your marriage at risk.
Try looking at things from his point of view. Would you want to put yourself in a position to be hurt again or feel used when you are not secure in your marriage. I am sure that he is feeling very self concious about why he isn't enough for you.
You really need to decide why you are still in your marriage. Is it just of convience since you are obviously not happy.
Good luck to you in fighting your demons.....