I started taking Centrum multivitamin and felt crappy before and after taking it although the Centrum DID give me hot flushes.
I stoppped it and take B12, Calcium/Vit.D, Magnesium and also Cranberry capsule as it helps with fluid retention and since taking the cranberry, I have had not one urine infection.
Prior to that, I was getting 10-12 urine infections a year.
None since taking Cranberry.
Try individual vitamins and stay off the multivitamin for a while and see how you feel.
In the meantime...get to a Doc and get a FT3, FT4 , TSH and antibody testing done for Graves/Hashi's.