I've been through this multiple times far too recently. My sister and my mother both died as the result of cancer, and just this past week a dear friend did also.

In all three cases, they were very much at peace with their impending deaths. They were ready to go, not because they were in despair, but because they simply knew and accepted that it was their time to go. My mother and my friend chose no further testing or treatment when it was clear that the treatment itself would decrease what remaining quality of life they had. Both were placed in hospice, and both died VERY shortly after being placed in hospice (literally within days). It was like they chose their time to go when they knew there were resources available to assist their families with their passing.

As far as your schooling, etc goes, would it be possible to ask the university for a leave of absence from your work while this is going on? Usually they are fairly accommodating under such circumstances. That might give you some time to deal with the immediate stresses and then return later when things have settled down. Sometimes the best thing to do for yourself is to cut back on those areas where you have some control to do so, and simply be kind to yourself while this is going on.