Red/inflammed meatus, penis lips (picture attached)

Hey people, My meatus has been inflamed for around a month now, its sensitive to touch, becomes more red after urinating (however no pain) & flares up a lot after masturbation. The worrying thing is that im seeing nobody has been actually diagnosed/cured from all these threads on this website - i'm seeing people have had this for years with no cure, what the hell is that about. I've tested negative for everything on the STD screening. Somebody tell me something PLEASE

image

what s your history, you recently had unprotected sex?