There is a condition that causes a person to swing from hypo to hyper. And some people are super sensitive to thyroid hormone replacement. It may just be that your dosing needs to be adjusted down. Are you seeing an endocrinologist and if so does s/he do a lot of thyroid care? Many endos do mainly diabetes and know very little about treating people with thyroid problems. I'm surprised the doctor is having you go in every week for blood tests. Thyroid hormone lasts a long time in the body and most of us have our labs tested every 4-6 weeks as it can take that long for a change to be seen when a medicine is adjusted up or down (or started or stopped). If you aren't already seeing an endo I would suggest getting a referral to see one (if you need it). It seems like you don't have a "simple" case - meaning a definite diagnosis that responds quickly to medicine. An endo may be able to pin point exactly what is going on faster and with less guess work.
I haven't been through what you have but I do know what it feels like to swing between hypo & hyper. We're here for you and please feel free to vent or ask any questions that you have. Welcome to the board :-)
Thanks Rayne for your commet. I have only gone to an endo for my thyroid. I am pretty sure that she does deal a lot with thyroids though. I know that the tsh takes at least six weeks to even change, but ft4 changes a lot faster then that. Since I am in the middle of my cross-country season, they are just trying to figure out what the heck my body is doing.