Should I see a dermatologist or a urologist for this bump on my penis?

A few months ago I noticed this bump/mass on my penis shaft. At first I thought it was a cyst but it doesnt hurt and hasn't changed in size. I've been tested for STD's and I'm clean. It is much more visible when I have an erection. It has essentially ruined my sex life because I don't want any girl to see this on my dick. What could this thing be? Can it be removed? And should I see a dermatologist or a urologist? Thanks.