Hi Tina,
Thyroglobulin antibodies are seen in high levels in Hashimoto's thyroiditis and in low levels like yours in Graves' disease. Anti-microsomal antibodies are the same as TPO antibodies, and they're markers of thyroid inflammation. Your thyroid hormone levels are high and your mild symptoms suggest that your levels have likely been steadily rising rather than abruptly changing.
Anti-thyroid drugs do help the immune system heal while lowering thyroid hormone levels. They're taken until you achieve remission and then, in most cases, thyroid function returns to normal although some people spontaneously move into mild hypothyroidism. Once your thyroid hormone levels are corrected and FT4 falls within the normal range, you won't lose weight easily although you won't necessarily gain weight. Weight gain while on ATDs is modest and with meds the dose is gradually reduced over time and eventually stopped.
With treatment that causes permanent hypothyroidism, weight gain is a common side effect and an average gain of 30 lbs within the first few years is typical. Because hyperthyroidism untreated can affect your heart, bones, and other organs, it's important to use appropriate treatment. And it's important to take charge and keep an eye on your thyroid hormone levels (keep copies of all results) to make sure that you're not over-medicated.
Autoimmune disorders tend to run in families and these include rheumatoid arthritis, diabetes, lupus, pernicious anemia, psoriasis and many other conditions. It could be that other family members have one of these other autoimmune conditions. Best, Elaine