You are correct that I was talking from clinical experience, but it was clinical experience with real people going through things, so it's still something.
Have you discussed your concerns with your surgeon? If so, what was the response?
It sounds like the issue here is that you are going through so much already that you have lost all of your confidence. I don't think the surgery is what will keep you from a partner as much as your fear and depression. I'm glad you are in therapy, because with everything you are going through, it helps to have a way to discuss all of these issues.
Suppose for a moment you won't be able to have conventional intercourse. I feel that is unlikely, but we'll imagine it. There are other ways to have sex, orally and manually and about as many ways as a human mind can imagine. So if for some reason you could not have intercourse, you could still have sexual relations with someone that could be just as satisfying. Again, I don't think that will be the case. But it may be that you are worried about so many things that you are throwing all of your energy toward worrying about this surgery rather than the rest of your life. That makes the surgery seem huger and scarier than it is.
I hope someone with personal experience will respond to your question. In the meantime, hang in there. You are having a rough time, but you'll get through it, and we're here to help. Please let us know how things go.