Robyn, I am sorry to hear about your mom. I have begun to rationalize life, or should I say death, as something that not one person on this earth will avoid. We all must go, and everybody is going to go the way they are supposed to go, whether its a car accident, heart attack, cancer, etc. Looking at death in this light has helped me deal with the losses I have suffered along the way.
This is why it is so important to not waste time and energy in negative ways. Why waste the precious seconds, minutes, hours, days, weeks, months, years away being depressed or angry about shit we have no control over.
Hang in there and, most importantly dont waste your time with emotions that keep you from living your life. I am not saying dont be sad, or its bad to dwell. MOST IMPORTANTLY, though your mom is still alive at this moment, so make sure that when you are spending time visiting her, whether she is awake or asleep, that you talk to her, get it out, because, though I talk to my dad and Hilary, and my grandparents all the time, it is different. Make whatever amount of time you have left as meaningful as you can/want. This is the best advice I can offer at this time.......My thoughts are with you and your mom......