Could you be pregnant? That could be giving you that rundown no energy feeling.
I don't know that i'd recommend an energy supplement without first talking to your doctor.
I'll admit, I drink 1-2 cups of coffee most days (I don't drink more than that because I'm nursing) and I notice a difference if I don't. I'm still waking 2 or 3 times a night to nurse the baby, though, and really don't get a full night's sleep.
Perhaps you need to go to bed a little earlier and try to get your 8 hours. Your day is so filled with energetic activities (just being the mom of a 2 year old!) that you probably need more sleep. Add to that that none of us are getting any younger... ;) It's a good idea to just try and get more sleep.