Can I get a hematoma in my penis from rough stimulation rather than bending?

[Jakeypoo12345]

I was having safe sex and it finished with a handjob. This handjob, though, was incredibly rough (very fast motions) and the grip was very tight - much tighter than I have ever done myself. While this was happening I ejaculated, and felt a pain in my urethra. This was far and above the most uncomfortable ejaculation I've ever had in my 27 years.

I didn't think much of it, but about 48 hours later, while urinating, I had a sharp pain in my urethra just below the head of my penis. This was followed by a dull burning sensation that has lasted until now (19 days). I was tested for STDs but everything came back negative. Took antibiotics anyways. Got tested again when symptoms persisted - still negative. No signs of sickness or anything abnormal in regards to my genitals (this was my doctors assessment). Also, I have loads of energy, I run every day, sleep well, and just feel very healthy in general.

Four days ago (after the doctor visit) I was doing a more thorough examination of myself and found something. On the underside of my penis, just below the head, next to my urethra, I found a dime sized purple lump that wasn't very pronounced. It is only visible if the skin is stretched and force is applied from the other side of the penis to push it closer to the epidermis, but it is very noticeable once this is done. There is no pain, but the burning sensation  in my urethra is coming from right about where this bruise is located. It's been 19 days and not much improvement from the burning! Note: burning is worse the next day if I masturbated the night before.  

Could the force of ejaculation through a very restricted urethra cause damage to surrounding tissue? Why didn't I ever see any blood? How long can these things take to heal? Will masturbating cause the bruise to persist longer/replenish? Are there other ailments that have these symptoms?

Thank you for reading and any help you may give!