Are My Symptoms Really Due to Something Else?

Anyone else's endocrinologist say that your symptoms aren't due to Hashimoto's disease or hypothyroidism bc your TSH is normal? I've had Hashimoto's for several years and Synthroid helps reduce the severity of my symptoms, but I still struggle with fatigue, low energy, feeling hot, headaches, brain fog, low fevers, and dizziness. If I overexert myself, I'll feel sick the next day, hence CFS. Doctors say there's something else going on but I've had so much bloodwork done and have been to countless specialists who cannot find anything else wrong with me. Are my symptoms really due to something else?