First, listen to your body. It is called "time off" for a reason -- a time to recharge, not shift full speed into working just as hard on something else. Yeah, I know, house, kids, other responsibilities. But you don't need to punch a timecard and devote the same energy level. You're not going to be fired from those responsibilities for taking an extra break here and there.
Second, if it is truly consistent low energy, high stress, talk to a health professional. You may need supplements, diet improvement, help dealing with stress, or may be depressed.
Third, if all else fails, and you have the opportunity, do as I ultimately did and retire early. Eliminate the stress and get your life back. I was extremely fortunate as I had my numbers, got my retirement benefits, was still in demand as a part-time consultant. Could pick my projects, say no, and earned as much as I was making for a third of the hours I had been working. My wife said I had been so stressed out that she felt she couldn't even touch me, and supported me in cutting the cord. Said it saved my life. Unfortunately, didn't save her from cancer.
