How To Get Rid Of Lump On The Underside Of Penis?

Hello, i am a young male with an embarrassing question. I noticed a small lump on the underside of my penis right under the head. It is only visible when erect and it swells up. It has a purplish color and is about half a centimeter across. I cant say that it hurts but it does feel a little sore. I am not sexually active but i do masturbate. I did some research and found that it might be superficial thrombophlebitis, but im not positive. I would like to avoid doctors and want to know if it will simply go away in time or if i can treat it with over the counter remedies. I would appreciate any help i can get. Thank you, Alex