@catherinebird - it can definitely be a challenge to find a dose that works without unacceptable side effects. I also found the 75mcg Levothyroxine - 10mcg Liothyronine dose to result in unacceptable side effects. BTW my doctor (naturopath, not an endocrinologist) explained that levothyroxine affects the T4, not T3, and that liothyronine is used to raise the T3 so you may want your doctor to explain how the levothyroxine impacts the T3. There is another brand of levothyroxine called Euthyrox that is blister packaged and does not contain any dyes. Not all pharmacies carry it but some Walmarts do and for me it was the same price as Levothyroxine. The pharmacy technician told me that patients who use Euthyrox say that it works better for them and they would not want to change. The package insert states that available doses include : 25 mcg, 50 mcg, 75 mcg but not 62.5 mcg. If you read the reviews on drugs.com, Levothyroxine (5.1 out of 10 from a total of 859 ratings) rates higher than Euthyrox (1.6 out of 10 from a total of 164 reviews). The UK regulatory agency MHRA issued a drug safety update related to switching brands of levothyroxine in May of 2021. So this is something to consider. I am not a healthcare professional so am just sharing information as patient.
Have you tried 50mcg? What is your Free T4 when taking the 62.5mcg Levothyroxine?
Wishing you good health and that you find solutions in the near future.