Urinary Problems?

I have been having problems with my urinary system for a little over a month now. At first I had lower back pain, burning while urinating, and a bit of urinary leakage when I stood (nothing major). I went to the doctor via televisit and they diagnosed me with a uti being that I have a past history of them. I had one in October that turned into a kidney infection and one in January of last year as well. After I had taken all the antibiotics for my uti my pee was still burning so my mom scheduled another Telehealth visit. The doctor told me I needed to come to the office and leave a urine sample so they could test for bacteria. The doctor called and told us that my Urine had no bacteria in it at all and referred me to a urologist. At the urologist I had to leave another urine sample. They cultured the urine and said they found nothing abnormal and no bacteria. They diagnosed me with bladder spasms and put me on a medication. My two week checkup is tomorrow and I’m concerned because my urine is still burning when I pee. I am 17 (almost 18) and sexually active. I have only had one sexual partner (which I have been with for around 2 years). I am not pregnant as I had my period May 14. I have had no prior discomfort other than the past month while having sex. I’m beginning to wonder if I have overactive bladder system which they diagnosed me with, or something wrong with my feminine parts. My period is irregular and endometriosis runs in my family. What do you ladies think I should do?