Painful yellow/white patch of skin which sometimes bleeds during intercourse

For about a year, maybe a bit longer, I have been experiencing pain during sex. It is only on the one side and is a raw type of pain as if it is an open sore. Usually if I haven't had sex for a while it hurts less the first time that I do again, after which it starts becoming more painful each time. It also causes bleeding most of the time. I have taken a look and I can see a patch of skin which is just inside the opening which looks almost yellow or white. Its not a bump. Looks like an ulcer. I did only start experiencing it after about 2 or 3 years of having sex and we have only had sexual relationships with each other so it won't be an STD/STI. Anyone have an idea what it could be? Can't go to gynaecologist at the moment and just want to know what it could be. I have considered trying an antibiotic cream but surely if it was only just a sore/ulcer it must have healed by now?