Panful and ***** lump on penis shaft

[aussie8648]

I woke up a few days ago to find a very sore, ~1cm in diameter lump on the shaft of my penis, which rests against my balls (underside of the penis). There appears to be a thin layer of what looks like puss sitting on top of the 1cm area, and around it is very painful, open skin, that looks almost 'raw'. I am unsure what this could be and would appreciate any and all help!

Note: I am sexually inactive and have never had sex (exclude STDs)

[aussie8648]

I apologize for the autocorrect in the title of the question, I did mean "painful". I also meant to write "pus" and not "puss"; my autocorrect apparently prefers to speak about cats.