After reviewing your sitch, here's my 2 cents worth:
I think you just have to trust he is telling you the truth and move on in that trust. The contant internal questioning seems to keep you "stuck." I know that seems harsh....but you have gained so much ground, from my perspective.....get unstuck! If someday, it turns out differently....he will confess the whole truth. I believe he NEEDS you to trust him now and go forward with that trust. Sounds like you are fooling yourself? Maybe...but try it out longer....convince him you believe in him and all he is telling you. If there is more buried inside him, he may come forward. If not....you then have to know you are on the right track.
Hang on and get through this thick MUD...it seems to be slowing your process.
