hi i had gone through your query and understand your concerns. i would come up with two most possibilities to fit your condition .these include
1.first possibility is,HYPOTHYROIDISM;due to stoppage of medicine your TSH
levels increased and cause your sufferings.blood test
for INCREASED TSH levels may confirm the diagnosis.
don't stop the medicine
2.second possibility is CERVICAL SPONDYLOSIS; is degenerative changes in the cervical spine
caused by hypothyroidism. MRI
scanning for cervical spine may confirm the diagnosis.
I hope this is helpful for you, thank you