You do need to see the doc again and have them do a thorough investigation as to what is causing your lack of energy. In the meantime though start on a good mulitvitamin as well as a good antioxidant supplement to help keep your immune system healthy. The doc needs to check more than just your thyroid etc so go back and ask him to run a full battery of tests to find out for sure if anything is going on. Also if the mulitvitamin you use doesn't make you feel better all around then you need to try a different one that does help you feel better all around. Your best bet would be to try one that has a money back guarantee so that if you don't feel better you can at least get your money back.