What Causes Swelling Of The Legs When Suffering From Thyroid Problem?

Question : I was originally diagnosed 75mcg levothyroxine for my hypothyroid. After 2 years I felt that it made me anxious w/insomnia. Without doctor approval or labs, I cut dose in half. Two months into 1/2 dose, I started getting ankle and leg swelling-hard non-pitting. Found out here that I should not have done and went back on full dose of 75mcg on 3/15/2014-15 days ago. Now, I am insomnia again. The swelling improved after a week, then yesterday hard swelling and now redness and burning in feet. I this now a symptom of hypothyroid, hyperthyroid or just IMBALANCE of thyroid levels in general? Thanks.

I know that I should not have messed with my original dose. I believe this is caused all the issues. My original TSH level was 4.50 I believe or around there. The doctor immediately put me on 75mcg - he did not take the dose up slowly. At that time I experienced lots of night sweats, anxiety, irritability, aggressive - quickly to argue, slightly swollen hands and face. I called and he stated that it was my body adjusting to the Levothyroxine. Having both testing I have had at annual physicals shows my thyroid at normal levels now. But still having the other symptoms, I chose myself to take my dose down as you can see from my comment. Then when I was told my Dr. XXXXXXX who confirmed your diagnosis, I went back to original 75mcg. It seem to help in the first week. Now the last two days, I have same type of swelling and burning-just woke up after 8 hours sleep and the symptoms are completely gone - feet look normal. But I am sure that as I am up, I will experience the symptoms again. Can you please tell me the best tests that I can have my doctor run to determine a good level for my thyroid? Thanks.