Depresstion symptoms and conditions

I a 49 year old male. A little while ago I was diagnosed with Hypothyroidism. My TSH was at 43. I have been taken Synthroid for a little over 3 months. I started with 25mcg and was recently increased to 50mcg since my TSH was still at a high 15. I also thought it prudent, since I had gained a lot of weight over the last year and a half, to also diet and exercise a little. In the last 5 weeks I have lost 32 pounds. (I was about 80 pounds more than I liked). I have more energy, have not lost anymore hair than normal, and my hair is not brittle. I have episodes of Atrial Fibrillation since I was 30 and occasional "heart flips" ever since. Since taking the Synthroid I have not experienced these "flips" at all. I sleep well. My blood pressure was High in the past and was taking two meds for it. Since taking the Synthroid (I'm also guessing the weight loss, diet and exercise has also helped) I am down to one med and I now have a BP of 110/65 with a resting heart rate of 64. By the way..I am taking the generic form of Synthroid.