The amount of thyroid med depends on the type of thyroid med you take. I was on 75 mcg of synthroid, but the equivalent dose of Armour thyroid is 45 mcg.
I can tell you that every endo I have seen has told me that 150 mcg of synthroid is the amount they give people with no thyroid, in other words, its the total replacement amount. Giving you too much is really bad. Perhaps your body is not using the thyroid hormone properly due to problems with estrogen/progesterone balance. You might try a third "voice of reason" by getting a consult with an OB/gyn who specializes in bioidentical hormone replacement. They got my thyroid down totally to normal and I feel great and take less estrogen. They claim women need progesterone to properly metabolize estrogen, that thyroid hormone can bind with the "bad" estrogen and so thyroid treatment doesnt' work well. I found this to be true.
I also had the same problems with my ANA and anti-thyroid antibodies were well over 1000. They are normal now and my ANA is still elevated mildly. I take plaquenil, which helps. I don't know if it has any effect on the thyroid antibodies at all. Synthroid and other thyroid hormone replacements are used for that.
My thyroid antibodies went down to 500 on synthroid, but went down to normal once I started using progesterone along with my estrogen. Even endos don't usually deal with estrogen/progesterone much.
It does sound like you are on to much of the thyroid, but it also sounds like you are insensitive to the hormone, you should be really sick from it, and like maybe a bioidentical hormone ob/gyn doc could give you some information to fill in the gaps and help you make a better decision. They also test all your vitamins and can also advise you on the vitamin D. Then you will have a more objective opinion.
There will be no way to tell if you have autoimmune disease, like Georgia says, while all this is a mess. The thyroid causes severe neurological problems, especially numbness in the extremities, and all kinds of problems. THe endocrine system affects every part of your body and arthritis and diabetes and liver disease can develop and all run rampant while this stuff is out of whack. Having high antithyroid antibodies can lead to hashimotos encephalitis, which can be life threatening.
I would definitely heed the endo, at least on the endo stuff, like the thyroid hormone. Try the bioidentical ob/gyn and get your estrogens tested and vitamins. Maybe you might do better on a full thyroid hormone replacement like Armour, rather than an incomplete, single hormone replacement like synthroid. You don't need to make a decision about the rheumie right away, just get some more info.
I hope you feel better. BTW Mary Shoman has the best thyroid site, and there is info about hashis encephalopathy. You might try checking there about your thyroid hormone dose.
Ills--Sjogrens-Lupus cond., AI polygland. dysfunction 2, hyper/hypopigment, scoliosis,kyphosis,stenosis, deg.,O.A.,spine surgeries, salivary/lymphectomies, NASH, COPD, RLS, UT/GI bleeds, hystero, brain/nerve damage,TB
Meds--INH,Plaquenil, Evoxac, Metformin, Synthroid, HCTZ, HRT and Lidocaine patchs, Voltaren gel, Klonopin, Vicodin, Restasis, Albuterol, steroids