I have these same exact problems too. I had blood tests and they found a vitamin d defieciency... all I need to do is take a vitamind d and calcium supplement to help with it's absorption. I already know I'm hypoglycemic and those are things that could be part of that as well.
More thyroid problem side effects also include mood swings, dry, brittle hair, thinning hair, among some of the ones you described.
Again the low iron (a sign if you are craving to munch on ice), or this could also be mild depression. Definitely speak to your Dr. so you can get everything sorted and get to feeling great again!
When you speak to the Dr, be sure to include things such as what you eat prior to your energy zaps, if you notice anything like weakness, double vision, if you feel better after you eat something, if you notice weight or cosmetic changes (such as hair...). Also, too much sleep can cause one to be tired as well.