If the results at the walk-in clinic were inaccurate, or if you were told something other than what the test said, you should register a complaint with the management and perhaps with the state regulating agency.
You might have started with your primary care MD but I would go with a list of symptoms as you have presented here along with the dates of your urinalyses and prescriptions. If you ask for a referral, don't ask for a phlebotomist as was suggested below - that's not a doctor and is just someone who draws blood for testing. (Your doctor might have to see one, but that will be in the lab to draw blood for a full work-up, which I agree you need.) A kidney specialist is a nephrologist, and a urologist specializes in the bladder. You might need either one, but you might need something else.
The TMJ is no fun - I used to have it and it caused the jaw pain and headaches. It can sometimes be lessened by wearing a night guard which can be made for you by your dentist, although I have seen some in the pharmacies which may or may not do the job. Obviously those are standard sizes and not customized.
The lower back pain could be related to the constipation or the UTI problem or both, or something else. It doesn't sound like it's high on your list of complaints but you should mention it to your doctor.
You've got a whole range of issues which sound to me like they are related to a suppressed immune system. The chills could be related to the fever, which could be related to UTIs, or they could be the sign of a reduced ability to just "fight things off." The nausea could be related to the UTIs, to the constipation, the exhaustion, and so on. A lot of people have this and it can be addressed with effective nutritional supplementation. But don't just buy multivitamins over the counter. Those are hard on the stomach and they aren't absorbed very well anyway. I can help advise you on this - I've worked with many people who had frequent UTIs, TMJ (like me), constipation and so on. Using a whole food product can regulate so many things and give you the nutrients you use, but you must look for high absorption and bioavailability. The existence of a patent is huge as well - shows proof of uniqueness and effectiveness and safety. You won't find this in stores but I can direct you. Because it's food, it will not conflict with meds or medical treatments.
Happy to help you more, and keep me posted on what the doctor says.