I can't add much, but I'm sorry you're in pain OP. I know what it's like to try and plead and defend yourself. I don't know what he read or what was written, perhaps he needs some time alone to sort his feelings out, and for you to sort yours out as well.

I had an experience where I had a very possessive friend, he cared for me but he didn't "want to share" - my time or my attention or whatever. This made it very difficult for him to accept that I had a bf. He found every reason to hate my bf, and to hate me for having him. A lot of that had to do with his own stuff. However, he took great lengths to sabotage my relationship which included going into my computer and deleting all my emails and then emailing my bf and saying that I had a sexual relationship with him (the friend). I had no leg to stand on now that my emails were deleted, my privacy was violated and it planted a tiny seed in my bf that I wasn't to be trusted (he had difficulty with that anyway) and that grew into a tree of unhealthy and terrible feelings. He never really trusted me again after that (very painful because I didn't do anything) and he started to feel that being in love with me was an awful thing.

Ultimately it hurt me very much that my SO gave any credibility to what my friend said, or that it was something he'd even consider. Sure I could understand why, but it was a unwinnable situation as I had no defense. It felt very invalidating, to feel like the person I was in love with thought I was a liar. There wasn't much I could do, how could I prove it? In reality, I didn't need to come up with reasons how to "prove" anything, my word should have been enough, my actions towards him in life should have been enough.

Give yourself some time to heal, some time to recuperate and space alone. In time perhaps some clarity will be revealed. Improve yourself and do things you want to do.