Hey Walken,
Just wanted you to kow that I am having the same problem as you. I feel extremely tired after finishing my minimal work requirements each day. I seem to have more mental energy than physical. I found it helped me to keep a tight bedtime schedule, watch my coffee intake, and in the evenings I walk around the neighborhood. I find this kind of wears me on out and by 10 pm I am ripe for bed. I dont sleep very deeply but I just ignore it and hope it improves. If my experience has shown my anything over the last month then I m sure it will... slowly but surely as long as I do something myself to help it along...take care...good luck