Very Dry Pain After Sex??

About 10 mins after I have sex or masurbate, the inside of my vagina gets really super dry and tight to the point where touching it hurts. Even trying to put a single finger in there is like being stabbed, and it's so dry and rough that sometimes walking after hurts. This dry painfulness can last from a few hours to even several days and it's become a problem with past partners because sometimes I can be having sex and be totally enjoying it, but after he pulls out for even a minute it won't go back in without a really rough, dry pain. I know that sex shouldn't hurt and I'm honestly concerned that this could be a health issue. Whenever I research it all that comes up is that it's a sign of menopause but thats highly unlikely considering I'm in highschool.