Hello there, I was reading your message about your vagina being too short. I also used to think that after my surgeries.
I had my rectum removed and anus sawn so with permanent iliostomy. After surgery and when I thought I was ready, my husband and I "tested" the new set up.
I had a short vagina ( or so I thought) as husband kept hitting the pubic bone and almost got injured. He obviously didn't want to upset me, but I felt terrible. He sort of found any excuse to postpone sex for a while. And that is so out of character, so I had to find out why it happened the way it did. I then started to look for solutions to stretch my vagina. Trying toys and "discovered" by using a dildo that my vagina hadn't shrunk but fallen back so to have a "comfortable slide in" my husband had to find the right angle to align with the vagina and avoid being "grated" by the pubic bone if the vagina shifted and closed. The pain we experienced only happened when misaligned. The specialist nurse at the hospital said that spooning from behind was the best position as it allowed for the correct alignment.
We tried all sorts of positions, apparently someone said reverse cowgirl would work, it doesn't! We both got injured.
So in summary, both my husband and I have always been very sexual creatures and tried all sorts of things and now there is only one position that works for the both of us as already mentioned and even then, he runs the risk of injury if slighly misaligned (wild sex is sadly out of the question), but I feel great and my vagina certainly hasn't shrunk, just fell back. Obviously if spooning is the only position (we've discovered so far) that seems to work, additional clitorial stimulation is necessary so get the "full experience".
Good luck experimenting. I had to get my husband to lose certain inhibitions. It wasn't easy especially in light of all my scars and the bag. But denying each other sex was just going to make us feel even worse (and me completely inadequate) so we had to try everything we could. Hopefully that advice helps someone.