How do I stop this nightmare?

My husband had an affair for 7 years with a co-worker. He eventually admitted to the affair when I confronted him, and has broken off contact. It has been 1.5 years since D day, and I still think about the other woman constantly. I'm haunted by comparisons between us, and even though my husband has taken Hope for Healing and is turning his life around after an almost life-long addiction to porn and masturbation, I obsess about the affair every minute of every day. I'm truly afraid he's going to leave me if I'm not able to get my feelings under control. I have been seeing a therapist and a marriage counsellor, which is helping, but there are days I feel so hopeless. I don't want to hide my problems from him, but it's also awful telling him how I feel and seeing his feelings of guilt; it's so discouraging. I wish I could end this nightmare. I've been married to my husband for almost 33 years now. I think I need the community of Harboring Hope to find others to talk to who understand what I'm experiencing. My husband suggested I join because this past weekend I was triggered and it turned into a 5 hour marathon session, while we were away on vacation together. I can't go on like this.