Penis pain when erect. What is it?!

Penis pain when erect. What is it?

For a few weeks now, when erect, I've been getting a very sharp pain in the shaft of my penis about 1/3 the way down from the tip. It's ok when left alone, but to the touch it hurts and during intercourse it's almost unbearable. When flacid, I feel a small bump in that area that I don't remember being there before. The pain and bump (or lump) is all inside the shaft as opposed to on the surface. There's no visible symptoms or problems urinating or ejaculating. I don't remember damaging or injuring it recently. I'm healthy, in my late twenties and monogamous. I'll go to the doctor, of course, but I thought I'd get some insight here first. Thanks!

Seek immediate medical attention. I suspect Peyronie's disease where the corpora cavernosa hardens which maybe painful and causes distortion and curvature of the penis. I hope all goes well for you. Good luck!