Agree with Jane. I'm glad y'all are seeing counselors and I wish luck with the sex therapist too.
The good news is there is a LOT of silver lining to your cloud. I highly recommend focusing on the good things going on as much as you can---it should lessen the anxiety you're feeling about this issue.
The silver linings I'm referring to is one, the loving/emotional aspect of your relationship seems intact. Everyone sounds very much happy and in love with each other. And two, you're still able to do sex with this partner at least somewhat. Like you said, you can still be a bottom role (and I would think he appreciates that as well as any foreplay/oral/etc than you do). Concentrate on the good there---you and him can still have a good sex life to a degree.
Give this time and try to remain positive.