I had a period of time after mania where I was totally not motivated and was basically lethargic. My Pdoc and Tdoc said I was exhausted from the weeks and weeks of mania, however I still felt like I "should" be doing things, but my tdoc convinced me that I needed to rest...period...end of discussion. I don't know if that's your issue? However even if it's from depression you need to give yourself a break. Do what you can and what you have to do from day to day, the rest can wait until you feel better.