What is the best and safest source of iodine product that i can use?

I have been diagnosed with Hypothyroid and my TSH is around 22, i have been taking 100 mcg of thyroxine every morning, but iam suffering from high acidity and reflux and high blood pressure and low energy levels, i still do my best to goto the gym and get some exercise done but i feel drained afterwards, i used to smoke and have minimised it and am trying to quit it all together, please help.