What is your thyroid problem?
I have been taking levothyroxin for many years. My GP reduced my dose by 20% in Feb. whereupon I became very unwell including extreme fatique, leg muscle and feet pain, burning, pins and needles. I just went back to my Feb. dose 6 days ago and I am beginning to feel better. It can take weeks to months to repair the damage. I could have been dealing with Hypothyroid Neuropathy.
I would ask your doc for your TSH, T4 and T3 readings. A high TSH for someone with a thyroid would indicate hypothyroidism with the above symptoms among many others.