When I exert myself or get really tired, I find I feel jittery inside.. and very tired. When I felt this way the first time was 3 years ago and was told I was dehydrated and was given potassium pills.. I rested and drank lots of gatorade and felt better.. But now I am exercising again and sweating a lot and I am achey and tired. Is this a vitamin deficiency or my hormones out of whack? I just turned 50 and was told I am in fact in menopause.