Hi, you are right to be unhappy as you were diagnosed 25 years ago but feel better on the T3/T4 combination, as many people prefer.
The worst thing doctors can do is adjust our meds according to the TSH, which I believe is very wrong indeed. Considering the TSH changes throughout the 24 hours of the day, so if you had a test every hour the TSH would not be the same. It is highest early a.m. and drops from then on.
It must be the biggest faux p aux in medicine to treat the patient according to the point were a blood test falls, instead of taking more notice of the clinical symptoms.
Your chronic fatigue may well be due to being on too low a dose of thyroid hormones.
I'd suggest making the earliest possible appointment for a blood test and ask for a Full Thyroid Function Test (GP may not do so and some labs don't if TSH is in range) TSH, T4, T3, Free T4, Free T3 and antibodies. Also Vitamin B12, Vit D, iron, ferritin and folate. Sometimes lack of vits/minerals can cause problems.
For a blood test, which should be the earliest and fast (you can drink water). Allow 24 hours between your last dose of thyroid hormones and the test and take them afterwards. This allows TSH to be at its highest as, has happened to you, they can reduce the dose.
Your CFS is most probably due to being undermedicated (I am not medically qualified but have had the run-around before being finally diagnosed as hypo, the.
You should get a print-out of your blood test results with the ranges and post them on a new question for members to comment. Always get a copy for your own records.
I am not medically qualified but had the usual run-around before being diagnosed and then the struggle to feel well on thyroid hormones but I'm o.k. now.
If GP wont do all the test, you can (if affordable for you) to have a private one through a recommended lab (one does pin-prick tests by post).