Dr's will probably redirect you to your established dx, but also consider Lyme. When infection is chronic/bad, the body sometimes can't keep up a high fever and switches to low body temp which could be a sign of sepsis. I had pain, low grade fever, fatigue and general unwell for decades. I became unable to work and there were no answers because there never will be in mainstream medicine for latent infections. I was misdiagnosed with fibromyalgia as is common. Then pain then required opiates, but I knew i was in real trouble when it eventually felt like heart attack sx coming on. Drs whispered sepsis without action. It took 25 years for me to be realize that all my Dr's who stated it wasn't Lyme were convincingly misguiding me, and for a good soul at the right time to say, 'sounds like Lyme'. It's the most controversial disease of our lifetime because millions go undiagnosed every year! Only a private LLMD has tests that work for old infections and are willing to prescribe helpful antibiotics. Most people with Lyme don't recall a tiny tickbite and never get diagnosed. Sx vary greatly bc there are multiple pathogens, but in general any combo of: brain fog, fatigue, malaise, pain, nuero sx is suspect. It's the new Great Imitator. My mainstream Dr's are starting to agree I have Lyme but still won't help. Don't be afraid to spend a few $'s, because avoidance is more costly. good luck!
Since you are on thyroid med and still have a low temp, and some symptoms that could relate to being hypothyroid, please post your thyroid related test results and their reference ranges shown on the lab report. Also, if tested for Vitamin D and ferritin, or serum iron, please post those as well.