purplish bumps/spots in male urethra HELP

I noticed this a few months back i was having a itchy/stinging feeling inside my urethra i opened the penis tip to look in side and noticed the spots its hard to capture on picture vs looking in person , some times i notice it more than others but its really annoying and they appear to be getting bigger.. i have had numerous urine tests , std, sti tests all which come back negative and every uroligst i see says " looks normal " has anyone else had this ?? if so what was it please help! picture in comment section

any update?