@karenzm
Perhaps switching too fast?? I think you have to give yourself a little bit of credit and time to get over the last medicine you were on! I just started with Exemestane, it seems like a better alternative than Letrozole. I will keep you on my radar and will let you know. Ask someone about the switching parts. That might be the culprit here. Ask you one oncologist, breast surgeon or plastic surgeon. They should be able to give you a heads up. Stay hydrated, and try propel water with electrolytes in it. Ask your doctor, but switching too fast is not clearing the medicine from your system before starting with something else. Time of day also might the key.

Again ask you three doctors.! Good luck!