I've been on Synthroid for 4 days now and I've noticed that I've felt completely exhausted during this time. So much that I haven't been able to go to work.. On .25mcg once per day. Also take Carbamazepine for Epilepsy but take it at least 6 hours after hypo meds. Not taking calcium or iron anything of that sort until at least a few hours after dose. What's going on?