Strep or STI??

So about a month ago, I both gave and received oral sex from a new partner. About 3 days after this occurrence, my throat began to hurt. It was red and swollen, and I had white spots on my tonsils. I went to the doctor and tested negative for strep twice, before they decided to do a third strep test. The third strep test came back positive (it was cultured, not rapid). I took a round of antibiotics (I’m not going to lie-I did not finish them) and of course I began to feel sick again after a couple of weeks. The doc prescribed me new antibiotics specifically for strep, and told me I would not be contagious 24hrs after starting the antibiotics. I have taken these antibiotics as instructed and I am still feeling sick. I unfortunately got a UTI from this, and I unfortunately got another partner sick. He claims to have tested negative for strep, but the docs are also treating him as if it’s strep throat. Has anybody experienced anything similar?? Can you test positive for strep but actually have an sti? Also disclaimer, I tested negative for mono, covid, and flu. And when my urine was tested, I tested negative for gonorrhea/chlamydia (however this was after the first round of antibiotics). Any ideas? Just strep?