Over-masturbation and penis pain

I am 22 years old and generally healthy and active. Four months ago masturbated three times in one day and my penis has been hurting ever since. Here are more specifics. After that one day my penis hurt mainly on the head. I did not masturbate for a few days, but then did again and it hurt. Then I took a couple weeks off in which I masturbated only once or twice, but very gently. This did not hurt too much. A couple weeks later my girlfriend and I tried to have sex, but this made it worse. I also noticed a slight bend to the right around this time. It was still mainly hurting on the head of my penis. So I took more time off, with only the occasional gentle masturbation. This was basically light touching and nothing else because anything more hurt and still hurts. In the last month I have masturbated like this probably less than five times, yet the pain continues. It seems that every time I have an erection it gets worse. It hurts all the time, in erection and not in erection. The pain is not just on the head anymore, but seems to be on the shaft as well. It continues to be bent slightly to the right (not when in full erection). Relative to my normal masturbation or sex once a day or less, I have taken almost four months off and yet it still hurts. I am worried that it will not get better. I have seen a urologist and they thought it might be an STD. I was checked and it was negative. I will be going back soon, but any advice would be greatly appreciated. For anyone reading this. Don't over masturbate. This is not fun at all and it really hurts.