Thanks--I'm thinking too it may be a fungal infection. Maybe even jock itch because I play basketball and sweat down there a lot. I will have it checked out.
The only way you'll know for sure what this is is to see a doctor.
It doesn't sound like herpes - its lasted too long. It could be a fungal infection, or possibly an allergic reaction to lube or your lotion when you masturbate. Even if you aren't using anything as a lube, I'd wonder if its on your hands.
Aj