I fell a few weeks ago while skateboarding, and landed on a railing. Went to the hospital and got an ultrasound(i believe it was only my testicles they checked) and it was fine.
When the accident happened I bled from the head, as if i were peeing only i wasn't.
The next day, i felt sore in my penis, and I had an erection that would not subside. This continued for a week until i decided to see a urologist.
He didnt know what was wrong with me.

2 weeks later my penis is still sore, however my full blown erection is gone, but I also cannot go back to no erection at all, there is still some firmness. Also it is still tender. If I try to get an erection it hurts again, but either way I still cant get a rock hard erection.
Im 21 this weekend, and before the accident i was perfectly fine so I dont believe i have any of those diseases.

Basically right now, my penis is firm, but not full blow, and still tender.