Help help help

I find that if I masturbate (pretty much any penetration even) my insides hurt.  It's not my vagina, it's higher up than that and it's like an a ache or a stitch, like whatever I'm using is pushing on it. It hasn't always hurt like that and I haven't had sex recently so I can't tell you if it's the same with sex. I'm so scared that I have something wrong with me or I won't be able to enjoy sex please can someone explain this to me?