Persistent NSU

So after having unprotected sex back in Jan with a friend, i went for a check up a few weeks later after i noticed slight burning aftr unrination. ( I have not had any sex since then)

Tests were clear for everything but positve for NSU.
Single 1g dose of Azithromycin was given.

About 2weeks later I had noticed that the symptoms had come back with a vengence. Penile discharge in the morning, more painful burning after urination, so went back to clininc.
Tested positive again for NSU and so they gave me 1week of Doxy.
Symptoms cleared up, but 1/2weeks later, noticed the discharge had come back and very slight burning.

Returned AGAIN. Tested positive for NSU AGAIN. They said the last meds were very strong and should have got rid of it, but they tried me on a combination of Azithro and Metronidazole for a week.

I finished this course last week and the symtpms didnt really go away, so i am gonna book another appointment, but i dont really wanna take another course of antibiotics as Iv heard prolonged antibiotics can get rid of your good bacteria and actually exacabate the problem.

I have snooped around on line and have read about persistent NSU and it can come back, but will eventualy go away with the correct treatment.

I begining to think they dont really know what theyre doing down at the clinic!!! and I really dunno what to do anymore.

Im worried coz it says if it goes untreated it can affect your fertility. Plus if you pass it on to your partner it can effect her fertility too!!