When I was in a similar spot I did like everyone else suggested. I made lists. One for home duties, one for selling the house, one for divorce, one for kid responsibilities, one for work, one for surviving. I have a day planner (on my computer) that I filled in and I always consulte that for appts. etc. through out the day.
Here is how I did it. At the top of the list I made the Goal.
Sell House - then I started writing things down that I *knew* had to be done. Then prioritize them. Then just put one foot in front of the other and keep moving forward.
If i didn't *know* it I did not right it down. My problem was that my lists would become complicated because I tried to predict the future so I'd have to make multiple sections of a list depending on a factor that had yet to be revealed. Or there would be three ways and I'd try to do all three. A plan A, B, and C so to speak and if I could get them running consecutively, all the better. The lists themselves became unmanageable. Well, I had to force myself to stop doing that. It mired me down, confused me, etc. I had to to this very consciously.
Also, the sleep thing is huge. A brain is not physically able to function if you have a chronic lack of sleep. This is a big big problem for me and has been for quite a few years. It is one that I need to watch closely. It is extremely easy/tempting/addicting for me to organize closets, do bookwork, play games, or surf the net all night long. The less sleep I get, the more I am drawn to do that.
I had to *make* myself go to bed. Look at the clock and just go to bed at some pre-determined time. I would lay there for 45 minutes and if I still wasn't asleep I'd get up and do 15 minutes of some kind of activity (not on the computer and not something like bookwork that could take half the night) and go back to bed. It did work and adequate sleep is important for brain functions like focus, attention, etc.