What should I do about the side effect of my tablets of dessicated thyroid?

Change thyroid med. Hypothyroidism, underactive thyroid, is always treated the same way. Find a thyroid supplement that is well tolerated and find the right dose (may take months) that brings you into a euthyroid (normal) state, then check levels every 6-12 months, to make sure, new dose is not needed. If treated properly, there are no side effects from the supplement; there are many brands (synthetic and natural).