I have had a thyroid problem for many years, and during that time have had lots of strange things going on. I have been on as much as 175 mcgs at one time with awful atrial fibrillation, now doctors have taken me right down to 100 which has brought other problems. The doctors do not want to know how I am feeling, everything is based on that standard blood test. I feel so bad now I want to try the change to T3. How do I go about it, and if I did what about availability of it . Do most people find a regular supply.How important is it to take temperature while changing over.