Levoxyl and prednisone

Wow - I just had an MRI today of my head and am scheduled to go through 3-5 hours of tests with a neuropsychologist next week. I have been on levoxyl with no substitute allowed due to this being the only drug that has leveled out my Hoshimoto's disease of the thyroid. My endocrinologist whom I saw on Friday suggested I see a neurosurgeon as "levoxyl can't be the cause of all your issues" which are identical to all of those I am reading about on here. I am a breast cancer survivor, take arimidex daily as well as xetia and a couple of other prescriptions for gastric reflux and anxiety. Now they all tell me that taking all these pills is fine as long as I don't take them all at the same time. Add today prednisone for the severe headaches - 6 at a time - I felt like a drug addict putting them all into my mouth at once. If this all is because of levoxyl I am going to be very relieved yet very PO'd that I have been told otherwise.