I'm 18 and yesterday out of no where I had a very sharp pain right below the tip of my penis. There are no bumps or redness or anything but it only hurts when it is touched. It's about a 1-3 on a scale of 10. I got a std test so I'm pretty sure that's not it and I can get an erection with no pain except for when I touch that spot and urinating is pain free. And I can't for the life of me figure it out. Please help