Infection but not UTI? Help!?

(IF YOU DONT WANT TO READ THE WHOLE STORY ILL LIST THE SYMPTOMS AT THE BOTTOM THANK YOU) So for the past few weeks, I’ve been feeling very fatigued, nauseous, aggravated (which isn’t like me at all!), I’ve been having to pee every hour of the day which is very annoying! It feels like I can’t empty my bladder all the way.. but I didn’t have burning so I didn’t think much of it. I’m 6 months pp and figured maybe it had something to do with that.. I did some googling and came across “silent UTI”. I went to the pharmacy and bought an at home UTI test strip.. I peed on it & it came out positive.. so I went to the doctor where I discovered I also had a slight fever.. they texted my urine and said my white blood cell level was high which meant I definitely have an infection.. I told him I’ve been feeling like this for awhile & was nervous it went into my kidneys.. I told him I didn’t have any back pain though.. he decided to do the tap test where he tapped random places in my back.. all was fine until he tapped one particular spot which actually made me gasp for air. He said “that was me touching your kidneys.” So he said that it was a UTI that traveled into my kidneys.. well the culture came back negative for a UTI 2 days later... I finished the antibiotic treatment despite them saying it was negative. The symptoms have not gone away, they didn’t tell me to go back? I’m not really sure what it could be then. Anyone have or heard of anything like this?

•constant need to urinate (every hour), feels like I can’t empty my bladder

•nausea

•slight fever (100)

•fatigue

•aggravated (not like me at all)

•bad back pain where kidneys are located (when touched/bumped)

•testing positive for high levels of white blood cells

•tested negative for the UTI culture

*symptoms have been lasting roughly 2-3 weeks besides he back pain where the kidney is, that’s been going on since Tuesday)