Blood after Masturbation

I'm 18 and a virgin and I've masturbated ever since I can remember. No vaginal penetration just clitoral stimulation. Well for the past few months, after I masturbate, I go to the bathroom to pee I've started noticing blood coming out. At first it was only a little bit but now it's a fairly considerable amount. I don't know what this means and I'm honestly terrified to find out. What do you think this means? What should I do?