Penis irritation on tip/meatus after urination or sexual contact

Hey everyone. hoping someone can point me in the right directions as I’m going around in circles from multiple doctors.

May 2023 the symptoms started 1-2 weeks after i had unprotected oral sex with a woman i was not familiar with (i made contact with this woman and she claimed to be clean.. and std free

symptoms include burning after urination, burning after sex or masturbation. and sometimes it just starts burning without doing anything.. and swelling in the urethral meatus

i have had regular urine /Std + hsv swabs & blood checks all coming back negative with no sign of infection.. last test was just under a month ago.
i saw a urologist who took a look at me and said everything was fine and to stop worrying. i now have a appointment with a new urologist in 2 weeks but it is starting to get out of hand.

has anyone experienced this before ? how was it treated ? and was it resolved after ?

your responses are greatly appreciated
**Edit/Additional question -
can trimethoprim or azithromycin cause a false negative on a urine std test ? only just a researched this now & im freaking out now..

Azithro x1 was given before my first test results came back negative at the start of symptoms.

trimethoprim was given almost a month after symptoms started 1x tablet for 2 weeks

thanks