Hello there, first post here (probably won't be the last because I'm extremely paranoid

)
Anyway, down to business....I'm 20, and have been an avid masterbator for a good long while. A few months ago, after a particularly good session,
I found my penis hurting...as if enflamed. I checked it immediately, and found a
red line under its crown. Obviously, I thought I was just being too vigorous, so I cooled down a bit on masturbating....
after 3 days, I did it again, and felt fine until midway into it...it started hurting again, and the red enflammation came back.
It's been perhaps 2 months now, and still I find it enflaming after a session of masturbation. I'm now using something other than my hand (For the sake of information, the Head Honcho), and it seems to help...but still I feel this growing pain...
especially while I become flaccid after ejaculation.
I tried Neosporin, and am still using it...only JUST got it a few days ago, so I haven't felt the effects as of yet. I really don't think it's any sort of disease...probably just bruising perhaps. But can anyone give me their opinion, and how to heal it?
Thanks in Advance. ^^
Oh, and just in case if the question is brought up, no I don't have a foreskin.