It sounds like you may need a course of hydrocortisone to support your adrenal function now. Taking thyroid med. you probably know can lower your cortisol, and thyroid and adrenal hormones have to be balanced to avoid uncomfortable symptoms. If you can lower your Synthroid without any ill affects to thyroid function, that might be enough to help the problem, but hydrocortisone may make you feel a lot better.
Definitely discuss it with your doctor.
Enzy
I had my pituitary check 5 years ago.
ok, I am stupid I just read that you have. I only ask because I suffer some of the same things as you but I have a rare lession that takes my entire pituitary stalk.
sorry I just wanted to help
jojo1966
Have you ever had your pituitary gland checked? if not I would ask for an MRI of this gland.
jojo1966