I have hashimoto's. i can't lose weight. i have high blood pressure and i have had periods of hyperthyroidism. why not eliminate my thyroid function?

Hypo/hyperthyroidism: From your question it is hard to know what is going on. Hashimotos thyroiditis and graves disease can coexist, and can yield intermittent hyperthyroidism. If this persists, radioactive iodine can be used to ablate the thyroid. But sometime the thyroid burns out on its own. If your thyroid blood tests are normal, then probably not causing your weight/bp issues. You need to see an endocrinologist.