Hi Cathhazard, welcome here to Beyond Blue
Touched a raw nerve this topic with me. Doctors will tell anyone with a mental illness that they need their sleep at least 8 hours a night. Shift work through my experience in security work is near impossible to cope especially on medication.
For you Cathazard its a balancing act and you really put your health at risk by not having some relaxation time ....rest. The result will likely be "burnout" or what seems that anyway. We will MI tend to run at a million iles an hour trying to chase the next challenge, find satisfaction from completing all the tasks only for another task arrive so soon.
I'm worried for you about the risks you might not see clearly at this point. On the other hand having insight that you have is a big plus. As some say "prevention is better than cure" and your anxiety....well best to pull out all stops so depression doesnt slip in through the windows.
Having said that your dedication to your brother is remarkable. Your post however reads that time is not able to be saved anywhere. If that is so then you need to harness this one day a week for full recovery of the other taxing days of the week. Plan that day well. Squeeze in all shopping and errands during the week knowing that your free day is filled with rest, sleepins and activity you want to do. Maybe a little study but not too much. Chill out with friends etc.
Make use of that free day.
Finally remember, circumstances change. In 2-3 years things will be different in all ways. So its not long term.