Just because T3 and T4 levels are in the so-called "normal range" doesn't mean they are normal for you... And do you know if they were Free T3 and Free T4 or were they Total T3 and Total T4? They aren't the same tests... the tests for the totals aren't nearly as informative. You should ask your doctor for copies of the lab reports. If you're in the U.S. your doctor is required, by law, to provide you with copies of all labs, upon request. I never leave my doctor's office without a copy of my labs and I keep them for my own records. They've come in handy SO many times.
I write on each set of thyroid labs, what medication(s) I was on at the time of the lab, as well as the symptoms I was having, so I know what levels actually suit me best.
I think if you had secondary empty Sella syndrome, they'd have called you to come in sooner. It sounds like your pituitary gland may actually be performing properly, it's just "flattened" and it's "compartment" is filled with spinal fluid.
If you can get copies of your thyroid labs and post them here, we can help sort out your symptoms... sounds like you're still hypo.
I haven't seen the endocrinologist yet for the empty Sella syndrome. I don't see him until May, so not for sure which one it is. They discovered it when they were doing an MRI on my cervical spine. I bought up to my Dr about checking my T3 levels along with my T4 levels, he said they had checked both and they were in normal range.
Have you been diagnosed with primary or secondary empty sella syndrome? Primary empty sella syndrome, often, causes no health problems. Secondary empty sella syndrome results from a tumor, radiation or surgery.
http://www.nlm.nih.gov/medlineplus/ency/article/000349.htm
High blood pressure, high cholesterol, tiredness and fatigue are all symptoms of hypothyroidism and may indicate that your levothyroxine dose isn't high enough or that you aren't converting T4 to T3 properly.
We can help you better if you'll post your current thyroid hormone test results. Be sure to include reference ranges, which vary lab to lab and have to come from your own report.