Tia,
I have been down a similar path to you as well.
What works for me and also some suggestions:
Firstly you can take your basal temperature each morning before arising to establish if your thyroid is in trouble. If it is low then the thyroid generally needs help. Mine was around 34.5 c. before I started any medication.
I learnt with trial that I needed "whole thyroid" a t4 t3 mix (similar to Armour) along with a herbal thyroid support and that thyroxine t4 didn't work at all for me. I now know through this forum that is because when you are mercury poisoned your body can't convert the t4 to t3. Even with whole thyroid I struggled, it helped but not enough. I have finally seen someone who knows what they are doing and they have quadrupled my dose of whole thyroid and tripled my dose of thyroid support because with candida and leaky gut my body can't absorb the tablets very well. Once my candida etc is beginning to get sorted then they will reduce the dose. I have to take care because if you are supplementing your body gets lazy and stops making any so it is a fine line of balance.
With the steroids, I wouldn't recommend them to anyone. Especially prednisone which can have some rather nasty side effects! Now I know better, you wouldn't get me to use a synthetic steroid for anything! I have been told that most (not all!) mercury women are estrogen dominant which is why I have found natural progesterone cream so helpful. (It is called natural because it is bio-identical to the progesterone in your body but it is not herbal!) Because it is bio identical and fits your receptors you don't get the same side effects that you do with the synthetic steroids.
Look at this link for more info
http://www.natural-progesterone-advisory-network.com/

See also Tgoss post on the "Getting Worse" thread.