Falling apart

I'm finding it so hard to keep myself strong at the moment like I know that I should. I have learned in my life that if I fall apart bad things happen although I don't know how any more bad things can happen.
My mother was diagnosed with cancer several mounthes ago and I have been her primary caregiver as her health has been declining. A week ago mom had to be rushed into the hospital with intense pain and nausea and they had to do emergency surgery on her bowel. Now we wanted that surgery over a year ago when the growths were first discovered but it was deemed too dangerous because of her heart problems. Now the surgery was extra dangerous and it wouldn't remove all the tumours, but she went throught the surgery ok and has been regaining her health and the other day she started walking and has now even been alowed food like soup and jello. It seemed like things were picking up but we were told that because of her health there was nothing that could be done for the tumours in her liver and the other one in her bowel. They said her lifespan should be measured in mounthes, not years. I'm deveastated of course but more then that I'm furious, if the bastards had just done the damn surgery mounthes ago then she would have stood a chance. I'm shaking with anger and nearing tears but I have to be strong. My dad is going through a hard enough time without me falling apart on him.
Besides I have to take care of my autistic brother, I'm not sure how much he knows about what is going on because it's so hard to comunicate with him. He used to talk alot as a child but now he's practically non-vocal. It's my responsiblity to take care of him and to help make sure that he's learning good habbits and skills like cleaning his own clothes or using both hands to pick up the dr. pepper bottle. I'm also trying to communicate with him and give my support.
Add to that I am at the casting stage at my play and the girls that I'm auditioning keep flaking out on me, I keep having one picked out only to have to choose another. Also I still have some finishing touches on the play itself, and chosing music and finding props there is much work to be done. My two women show is just starting to stand on it's own tow feet and i can't give up now. It's really shapeing up to be a beautiful love story.
Add to all this my stupid tomach is chooseing to act up and the dizzy spells and shakes are back and I just do not have time to be falling apart now.
So all and all my life is a epic fail at the moment.