I'm 70, And Three Years Ago I Was Having Terrible

I'm 70, and three years ago I was having terrible time with short time memory, brain fog, fatigue, etc. My PCP found my thyroid was off (can't recall if low or high). He put me on 45 mg per day of Thyroid medicine. My brain cleared up, and fatigue was better. It is back now (I've moved away from my former PCP), though not as bad, BUT I've gained about 25 to 30 pounds! I'm a small man, and have never weighed over 165, and now weight 188. My blood sugar is creeping up, though still ok, and the same with my blood pressure, creeping but still ok.