T3 has a short useable life in the blood (it is useable only for a few hours), and T4 is stored in the cells until needed. So, we usually need adequate T4, at least, if not added T3.
It takes four to six weeks of a consistent dose of T4 before the cells are saturated at that dose, which is why I suggested that the T4 you have been taking may not have saturated your cells yet or your dose may still be too low.
I was taking Armour which has both T3 and T4 in it, plus pure T3 (Cytomel). But my T4 level was still low, and I was symptomatic, in spite of the T3 I was taking.
My doc cares about the FreeT4 level, too, and so backed off the pure T3 in order to add more T4 to my dose, because my Free T4 was quite low. Translated, what this means is, we stopped the Cytomel, and raised my daily Armour dose, which means the T4 was considerably raised, and the total ammount of T3 was lowered a little.
Try taking selenium, no more than 200 mg a day for a couple of months, to see if that helps your symptoms and blood levels. It often does. It really makes the difference for me...we cannot convert T4 into T3 without adequate selenium, and not knowing where our food is grown anymore, we don't know if we are getting enough of it.
__________________ Tree Frog