I have been struggling with this myself. I try to rationalize, pray, forget about it ... nothing really works. Bummer when people indicate it's about me ... like self esteem or something. I seem to want a fix outside of myself; like if she could undo everything she did, or prove something to me. Like I'm waiting for the secret words.
Whatever truths I can muster from this whole thing--like, I must accept reality; I must forgive her and love her for everything she is, etc.--I still fall into mental pits where I just obsess about her past sex life. It totally sucks. It's like the worst thing in my life right now.
I don't know if this helps, just to know someone else feels the way as you. I guess it helps me to read your story.
There's a hole inside me that only God can fill. I believe this trial is a way of learning. I am looking for my fiancé to fill a void; but she does not have that ability. I am longing for peace and looking in the wrong place; I keep doing this out of my own will; I have to stop demanding that she be something she can not be.
I learned: One way to cut the umbilical chord is through sexual abstinence. Clearly sex has a command over me or I wouldn't be obsessing with my girlfriend's past. Nor would I need sex if it didn't control me. My own promiscuity before marriage indicates I am longing for something. Must I fall to the desires of a fleeting moment?
A selfish way of looking at this is, abstinence seizes control. In reality, it's just putting control back where it belongs. It's one way to right the past.
If you and your boyfriend had abstained before, you wouldn't have this problem. Demand that you abstain now. You will both appreciate your relationship.
Best to you ...
