I don't deal with it very well either. Patience is the only way through it. Accepting that my memory is only seconds long sometimes. Accepting that I may have to put off something until I can concentrate helps. I don't live by a schedule, I live by when I can do it without stressing out about it. I don't have a job, so I don't have that pressure. My wife helps a lot, I don't do anything with the household finances, taxes, bills, groceries, etc.
One day I may be able to do pretty much anything I want, then the next, I can't do hardly anything. It may even change mid day, or hourly. That's my life now, no sense in fighting it.
Communicating with the Mrs. how I am doing if I'm having trouble with any of my conditions helps too (PTSD, anxiety, fibro, depression, pain meds, lack of sleep). That way she knows for the most part what I can do and deal with.
I hope this makes sense. I'm having difficulty today concentrating. Lack of sleep, pain meds, fibro day.