How To Treat Dizziness And Fatigue Caused Due To Hashimoto S Thyroiditis?

I m 28 years old recently diagnosed with hashimotos.. Currently taking natures thyroid for 3 months now.i am a heavy soda drinker too...the past few weeks I have been feeling exhausted run down.the dizziness has gone away. But now my muscles are so tired..like feels like I worked out fro hours.not sore just tired and restless..legs arms ect.massage helps but only while I m being massaged.then it s right back to how I was tired and weak muscles.after lunch I have noticed that about an hour later I m extremely drained, need a serious nap no matter what I eat.any ideas...as to what this is or what is causing these symptoms? Please help