I'm an 18 year old male and i'm just looking for some advice. I can pull my foreskin completely back when i have an erection (it doesn't slide over freely I have to pull it down a bit) but it hurts when i try to have sex as if its being pulled really tight. i'm just wondering what i should do about the problem? as im not 100% sure what the problem is.

Anyone out there with any advice for me it would be greatly appreciated.

Cheers!