Finally got my bloodwork....it's only been since December that I was supposed to get tested.....

long story, haha.
Anyway, results:
TSH - 5.54
Free T3 - 3.3
Free T4 - 0.91
First time of being tested for Free T3! Yay! I know the TSH is way too high, and the Free T4 is too low. I have no clue on the Free T3, since I've never had that tested before.
So questions - and forgive me if this has been asked before - what kind of symptoms does low T4 cause? And, does anyone know WHY "brain fog" is a symptom of thyroid problems? Like what causes the brain fog, and is there a way to "reverse" the effects. I feel like the brain frog is worse now than ever. I'm hoping to get in to see my doc next week with the results, and I know he's going to run Insulin resistance and thyroid antibodies.
One more thing. I used an online site called
My Med Lab to order my tests. I was a loser and lost my original script from my doctor ordering these blood tests, and my doc's office would not issue another script. I didn't want to pay for another appointment just to get another script, so I'm SO glad I found My Med Lab. They were very reasonably priced - about what I pay all the time anyway.