Why There Is Bruise Like Pain In My Penis Shaft?

I recently have this bruise like pain in certain areas of my penis shaft. Its right below the head of the penis and when touching it hurts slightly similar to a bruise. The area that hurts also feels harder then other areas around it . When flacid the penis looks slightly swollen. Ive had these symptoms for the past 2 weeks and remember having this before but it went away eventually. This time it seems to linger much longer then i remember. I wonder if its injured from sex or masturbation. It also hurts more when its erect but when only pressing on the area. What could this be?