After a long absence, I'm checking back in here. First of all however I must apologise to those who messaged me and responded to my questions, to whom I never replied. At the time I had just become so depressed about my condition(s) and that no-one in the medical field was taking me seriously, that I just had to remove myself entirely from anything to do with hypothyroid and its associated conditions. So again, sorry about that, people!
I'm back now with my latest test results which prove that T4 meds alone are not sufficient. My T4 is now 12 - the lowest end of acceptable, and the lowest it's ever been - and my TSH 0.77. The GP refused to test for hypopituitary, but finally agreed to give me a month's trial of T3 meds. So, it JUST had to get to the stage where I've gained 35lbs in half a year, am fogged up, zombified, exhausted, am losing what's left of my hair and outer eyebrows, extremely poor circulation, frequent break outs of acne, and permanently dizzy and anxious, and be borderline T4 deficient, for them to take any action. Jeez Louise...
So, finally, I walked away from the GP's surgery with a rx of Liothyronine! HOWEVER, I get to the pharmacist and they tell me basically what I've been reading here; that there's a distribution problem with T3 meds right now and they have no idea when they'll get any. Fortunately, last December I had purchased Cynomel from a website recommended by several members here (but had declined to take it because..well.. I got scared basically), so I'm going to take that for the time being. I'll let you know how I get on.
Hope everyone's having a good day