I agree with gimel that starting at 175 mcg is not a good thing. Many people have issues when starting at such a high dosage.
Do you have a copy of your lab report, so you can post your actual test results? Did your doctor test you for Hashimoto's Thyroiditis, which is an autoimmune disease that eventually destroys the thyroid, so it no longer produces any hormone at all. Additionally, have they done an ultrasound to check for nodules?
Again, I agree with gimel - if your doctor is determining your treatment based only on TSH, you may have to find a different one. Alleviating symptoms is the top priority and that's best done by adjusting FT3 and FT4.
So glad to hear that you may finally have been properly diagnosed and started on the road to feeling good. Just wanted to mention a couple of things. First, I hope the doctor did not start you at 175 mcg. That would be far too much, in my opinion, and could be a contributor to your sleep issues. Many members report having reactions to too high of a starting dose. Since it takes about 6-8 weeks for a T4 med to build up in the blood to full effect, you could be at too high a level, if you continued with 175 mcg for another month or so before re-testing. I would think that 50 mcg would be a far better starting dose, with re-testing and dosage increase in 6-8 weeks.
Second I hope that the doctor did more testing for thyroid than just TSH. TSH is a pituitary hormone that is affected by so many variables that it is inadequate as a diagnostic for thyroid problems. At best it is an indicator, to be considered along with more important indicators such as symptoms and also the levels of actual, biologically active thyroid hormones, free T3 and free T4. FT3 is actually the most important because it is four times as active as FT4, plus studies have shown that FT3 correlates best with hypo symptoms.
In my opinion the best way for a doctor to treat a thyroid patient is to test and adjust levels of FT3 and FT4 with whatever type of medication is necessary to relieve symptoms, without being constrained by resultant TSH levels. Symptom relief should be all important, not TSH level. If you doctor has a problem with treating your symptoms in this manner, then I expect that you will have to find a good thyroid doctor that will do so. If you were only tested for TSH, and then started on 175 mcg of meds, then I think it is clear that you need to find a good thyroid doctor.
In addition, I'm on 175 mcg of Synthroid a day.