I hate to beat a dead horse,

but the one thing that helps my energy level more than any other is to get moving.
I joined a womens health club (very reasonable $ in my area), I go at 5:30 am before my day really starts, and it really does help. It's only 30 minutes of exercise so it doesn't require a great deal of time. If you can, walking is a very good start.
But... if you are doing nothing, starting may something be difficult. Stick with what ever you try. Good luck. b