Hi,
I would like some advice.

My mother has had an underactive thyroid for most of her adult life, although only recently diagnosed.

Although I have had blood tests recently to check, which have come back 'normal' (but fairly borderline according to levels), I still have many of the major symptoms of an underactive thyroid.
At 17 I became very ill with what at the time was ME/CFS. Before this period, I rapidly put on a lot of weight.
Years later, when enquiring with my doctor what levels my thyroid were at that time, they told me they never did a blood test for thyroid (which amazes me!)

I have recovered from the ME/CFS but still suffer from strong bouts of depression at times, fatigue, difficulty in losing weight, although trying very hard and low energy.

Over the last few weeks I decided to take a very small amount of levothyroxine - equivalent to 20mg per day. (without the GP's knowledge) It is the best i have felt since before I first became ill. My moods were stable, I had energy and the fatigue lifted. I had no side effects and just felt 'normal'.
After about 6 weeks I felt that I should not be on it without the GP's approval, so came off it... and since, I have felt back to my old self; depressed, exhausted and lethargic.

I'm not sure what to do. Will they just dismiss my experiment, or could it be that maybe the quality of my bodies thyroxine is poor, hence the improvements?

I would appreciate some advice.
Thanks