The symptoms you describe are classic bromine detox issues. The older you are, the more likely you've had a buildup from exposure your whole life. Water and salt are going to be your friends. I found benefit using both Iodoral and SSKI, as Iodoral in doses around 100 mg started gumming up inside me -- that's how it felt, anyway -- and SSKI helped thin that gunk back out so I could metabolize it. I still like a balance of both. Ginagirl gave you the link to Breast Cancer Choices, which has a long list of bromine detox symptoms and instructions for salt loading. If you don't care to take salt regularly, you can use it on an as-needed basis. We recommend 200-400 mcg selenomethionine if you haven't supplemented with it before. That will help protect you against Hashimoto's, as will being gluten-free.
TSH 3.44 is nobody's optimal. Some people do very well tuning up their supplementation and taking iodine. Others, such as myself, need additional thyroid support. That does NOT include Synthroid, but does include natural desiccated thyroid with both T3 and T4, as well as T1, T2, and calcitonin. I think a thorough course of detox will help you know how much, if any, additional thyroid help you'll need.
For your high MCV, consider that you may be low in folic acid and/or B12 (macrocytic anemia). A therapy for that can start with 1 mg folic acid and 1 mg methylcobalamin B12. For good thyroid function, aim for serum B12 > 800 and serum ferritin 70-90. Good luck!