raising a sick child, afraid of the future

Raising a sick child is difficult without a doubt. I'm still figuring out how to make sure my son's quality of life -- after I die -- remains acceptable. So far, I've gotten little progress and I'm worried of whatever's to come. I definitely don't want to give my older son the responsibility of looking after his little brother, but it seems that I'd have to. It's unfair for my older child and my younger boy should be in a better position to care for himself fully (http://project05952381.blogspot.com/2010/09/yet-another-blow.html).