Struggling with Chronic Illness: Which Conditions Should I Consider First?

Struggling with a multitude of symptoms, they are getting worse over time, I started getting sick in February 2021, it started with what felt like the flu with a really bad headache. Sore, weak, tired, sinus drainage, the general I don't feel good symptoms. I got diagnosed with a sinus infection, took the antibiotics. they didn't help but I started to feel better a within about 2 weeks so I didn't think that much of it. until I have been diagnosed with 7 more sinus infections, the list of symptoms keeps getting longer, I can barely walk now. I got a rolling walker today through the insurance company because I have fallen so much. The ENT says there is no sign of sinus infection, or sinus damage, or anything sinus related causing the problem. I am frustrated, 31 years old with so much pain and weakness I can barely get to the doctor. I am going to list out the full list of symptoms below. I am having to fight for every test to try to find out what's going on. my question is which conditions should I consider first?