pain during sex!! help!!

okay SO for starters, it's not the initial stretch of my vagina that hurts. when my boyfriend puts it in, there's a certain point that he hits that is like a pang of hurt. like it feels like someone stabbed my vagina or something. i don't know if it's the hymen or what, but it's like a wall of pain that is seemingly impossible to break down. i also just have a low pain tolerance so that isn't helping. i have been trying to google what the hell is going on with my vagina but i haven't had any luck. does anybody know what this could be? does anybody have any tips on how to reduce that pain/break down that wall?