Added this update to my original post then realised I'd be better off starting a new post.......
Well following the great advice people on here gave me, I went back to my GP and asked to be retested. I got the earliest appointment and fasted and the results were almost identical to the original ones I had done with Medichecks! Here's a summary of the results -
21st March - Medichecks:
TSH 7.52 (0.27 - 4.20)
Free Thyroxine 11.81 (12 - 22)
29th March - NHS
TSH 2.5 (0.35 - 5.5)
No other results on printout so I assume Free Thyroxine wasn't tested
12th April - NHS
TSH 7.56 (0.35 - 5.5)
Free Thyroxine 13 (9 - 23)
GP was going to do nothing as free thyroxine was in range but I said he had to do something as I feel absolutely dreadful! I now have a trial of 3 months of 25mg levothyroxine and have been taking them every morning, an hour before eating, for the past week. Having read so much on here, I have ordered a test from Medichecks which also will test FT3, TT4 and the TGAb and TPOAb antibodies.
Am taking Vitamin D3 (10,000 IU per day) and B12 (1000 ug per day). I also have some ferrous sulphate I am taking to raise my ferritin levels.
My GP told me to come back in 3 months to be retested. Does that sound reasonable? Any advice on what I should be doing now would be much appreciated.