It might be unrealistic expectations. Actually, when I first started taking vitamin B12 (due to a vitamin B12 deficiency)... I experienced a hit by a truck fatigue for acouple of months... as apparently my body was busy repairing nerves and it can take a lot out of you.

I've never really found anything to make me energetic... I'm hypothyroid too, and although treated... I think I'm destined to never feel as energetic as I'd like. Exercise does help my energy level a little... but I never seem to stick with it... more on and off when it comes to that.