Poor you jaff with both parents shouting at you
Dont beat yourself up for shouting back - you are human, not a robot and we all snap eventually. If she starts being unpleasant the best thing is to just walk out of the room, but its difficult to remember in the heat of the moment.
Im glad that the hospital has got your dads food sorted out. If hes on a soft diet dont worry too much that he didnt want the banana. Everyone has good days and bad days and he may decide he wants a banana tomorrow!
A third vote here for you to have a holiday - if you burn out you wont be able to help either of your parents.........