All right, my boyfriend of one year and I used to have sex all the time, multiple times a day, and now I can't have it at all. It hurts so bad, and it won't barely go in. Why?

Vaginas don't close. It's possible you tore your hymen and its just healing, if that sounds possible, just give it a few days. Make sure you want it, it's harder to go in if you don't. Otherwise visit your doctor.

? Tore hymen and still hurts after lots of sex?

Ok, could very well be an infection, seriously time to see your doctor.