Your problem could be due to 2 reasons mainly:
Firstly it could be a part of the hashimotos disease .... although such symptoms are more common on the right side rather than the left in the disease.
Secondly it could be due to migraine
In either of the case it would be best if you consulted a neurologist
for expert opinion.
Going for a CT scan
would be advisable.
As for the joint pain I would suggest you to go for a complete arthritis
panel and start medication accordingly.
I hope my advice has helped.