What Causes Weight Gain Along With Mood Swings Post Thyroidectomy?

Hello, In August 2014 I had surgery to remove a parathyroid, whilst the surgeon was operating he noticed a lump in my right thyroid gland of which he removed. The lump turned out to be cancer and 4 days later I was back in surgery having that thyroid gland removed. In September 2015 I had gain a lot of weight and my mood swings and patience were terrible, I had a blood test and was put on thyroxine initially 1 x 50ug a day which did nothing and now 2 x 50ug Mon-Wed then 1 every other day. Nothing has changed and I am loosing faith in my Endocrinologist. My last blood reading was TSH 4.1 ad T4 was 13. I m seriously considering going off the medication and seeing a natural herbalist, I have also last week put myself on 600mg of magnesium, D3, and K2 as well as Iodine drops 1 x 216mcL dose per day. Any helpful advise would be much appreciated.