When you switched to PTU, what was the dosage? Also when diagnosed as hyperthyroid, how was it described, as to severity? The reason I ask is this data.
Usual Adult Dose for Hyperthyroidism
Mild hyperthyroidism: 5 mg orally every 8 hours.
Moderately severe hyperthyroidism: 10 mg orally every 8 hours (up to 40 mg per day).
Severe hyperthyroidism: 20 mg orally every 8 hours.
When you tested as having .005 TSH, if also tested for Free T4 and Free T3, please post those along with their reference ranges shown on the lab report.
I am not real familiar with antithyroid meds like Methimazole and PTU, but the 30 mg dose of Methimazole seems to be for severe hyperthyroidism. Anti-thyroid meds do have side effects that include joint pain, but it also seems to me that such a high dose could drop your FT4 and FT3 levels quickly and cause joint pain associated with being hypothyroid. I read that Methimazole and PTU both have skin rashes as a side effect. I expect that this would be more likely with a high dose.
When I look to see the conversion for Methimazole to PTU, it appears it is 10 to 1, so It seems that going from 30 mg of Methimazole to the 100 mg of PTU would be a significant reduction. So I think you should discuss your dosage with the doctor and make sure that such a reduction was intentional. I think you also need to get the doctor to test you for the biologically active thyroid hormones, Free T4 and Free T3, and determine what your current levels are.