I don’t know what’s wrong with me

So I’ve been having UTI’s since I was about 15 and that was around the same time I started having sex, so I always thought the two were correlated. I’ve probably been to the walk-in for a UTI about 30 times. I never had blood in my urine but I always had the severe abdominal pain and the SEVERE burning and frequency of urination. The most recent time, I did the same thing, and getting fed up, I told the doctor that I needed these infections to stop because they were literally ruining my life and he took a minute to look at my medical history to figure out if something was wrong. He looked at my history, and out of the 30 times that I’ve been seen for a UTI, the lab tests only came back to show that THREE of them tested positive for a UTI. So clearly, UTIs aren’t even the problem. My doctor told me to go see a urologist. I saw a urologist and they cultured my urine, finding no irregularities and I got an ultrasound and a cystoscopy (where they look into your urethra and bladder with a camera) and there were still no irregularities found. My urologist prescribed me a temporary amount of small dosed antibiotics to take every day, and when the bottle runs out to stop taking them completely. My bottle ran out about a month ago and I am STILL HAVING PROBLEMS. Has anyone had something similar happen to them? I just feel like I don’t have any options anymore.