4 years and still hurts

My SO and I have been together over 4 years now and have been having sex majority of that time. He is the only guy I have (and hopefull will ever) been with but he was in the double digits before we got together. My question it; 4 years later and it still hurts, 95% of the time, we have tried condoms, lube, positions and a bunch of other things but nothing works. Ive seen a few doctors about it and so far all they can suggest is everything we have tried and this vagina stretcher thing that I would put inside of me to help stretch it 😶🙃😕😖 he feels so bad all the time for hurting me and now because of the problems of it hurting and me splitting theirs scarring to make it worse. I just dont know what to do anymore