I had unprotected sex last night with this girl who I ve slept with before. Again, after sex, my foreskin is completely pulled back and the head of my penis is red and swollen, and on the underside of the head, there is this swelled up bubble thing. It is very sensitive, and every time my penis touches anything, it hurts. After last time, it was okay. I was wondering why this is happening again, and if I am going to be okay/ what I can do to fix this problem.