My heart goes out to your fiance.... Trust is a really tough thing for us Survivors, and having an abuser break that trust would be horrible...
I think your fiance really needs a therapist to talk with... I'm sure he's blaming himself for what happened as a child, and now as an adult.
It makes sense to me that your fiance would be having nightmares and is questioning his sexuality... There are probably many other ways he's been affected but he doesn't see...
I'm glad he has your support in this... I wish I had a way to make the pain go away, but it's going to take time...
Thanks for being there...
tat2bear