Charles, I had an energy issue during and immediately after rad/chemo as well. Turned out it was blood issues with the white and red cells. My counts were in the toilet. They put me on Procrit for 8 weeks to get my counts back up and that took care of it for me. Procrit is very expensive ($800 per shot, 1 shot per week, 8 weeks), but my insurance paid for it. You might want to check with your oncologist because I had to ask for it, even though my cell counts were so low. Are you having radiation along with your chemo? If so, there may be some additional "surprises" coming. Rad is an interesting treatment and can have some interesting side effects. Hope all goes well.