Painful sex

I lost my virginity about a year and a half ago so it's not like I'm new to sex but every time my s/o and I try to get intimate, it hurts. I've even bought lube and used it. I've asked him to go slow and he has. Nothing seems to work and it's honestly frustrating because I always have to stop after a couple minutes of sex due to the pain. My vagina is also sensitive for days afterwards. Any suggestions?