What are the differences between an endocrinologist's thyroid testing and a GP's?

I still think I’m hypothyroid. Two general practitioner’s CBC tests say my thyroid is normal. I don’t believe that. I ‘ve heard that an endocrinologist’s thyroid panel is much better, much more sensitive than a GP’s. I have loss of hair on the outermost part of my eyebrows, my knees are weak, I have double vision on the left from “10 o’clock down,” and tinnitus 24/7. Would an endo’s thyroid panel be much more likely to detect hypothyroidism?