800 mg would be wayyy too much......at least I hope that is what she meant! deformities can happen differently with different people depending on how severe your RA is. And then you have to worry about joint replacement surgeries and such. My doctor told me not to be scared of the methotrexate. He said my immune system was in worse shape before I started taking it. He said most of the literature out there on methotrexate is for high doses in chemo patients. For RA you are on such a low dose that most of those side effects dont even apply to it.
But, some people react different to different meds. It may be what is causing your hair loss or it may just be the RA in general which means you may need to consider getting back on mtx or trying a DMARD. It could be a combination of things ....thyroid, anemia, and RA together. I really feel for you as none of us want to lose our hair!
I hope things will improve for you soon!