Hi Barretsark -
I had a terrible experience last spring when my T4 medication was increased. I got incredibly ill and have only now (November) started to see some improvement. I think I can understand how you are feeling and how desperate you are cause I have been there. Doctors do not understand what they are doing when they medicate with T4 and test and test and test. (In my opinion, of course.)
I am afraid I cannot explain to you what is happening with your thyroid, but it is definitely adjusting because of the changes in medication. And, that is why you are feeling like poop.... I think.
I always send people to this web site for answers:
http://www.realthyroidhelp.com/
Sometimes the T4 thyroid medication does not work to fully make you feel better. I know this from personal experience, but I guarantee you if you take this in to your doctor they will tell you I have no idea what I am talking about.
Finding the right dose of medication takes a long time and I wish you good luck!
(Visit that web site when you can!)