Well....I had missed a few days of my synthroid because I was on ...

Well....I had missed a few days of my synthroid because I was on vacation, and started to feel really sluggish and just "off". I had a thyroidectomy a few years ago due to a growth in my thyroid that was only getting bigger. So...after reading all of these, the few problems I have been having over the years (hair loss, insomnia, horrible leg cramps), have gotten me worried. What are the options for someone like me? Who doesnt have a thyroid? What happens if I totally STOP taking this?