((((((Nikko)))))),
Honey, I know how overwhelmed you feel. It's beyond hard to be the sole caretaker of an elderly, ill parent. I had two half-brothers left when my mom was sick and dying. One was watching his Father die at the same -- he was incapable of doing any more. The other is just plain useless (I've given up on him; he's old enough to know better).
Please don't think the big S is an option. There are other options that will bring you much more peace.
I know the guilt trips that parents put you on

From the time I was 12, my Mom always said "no nursing home" and "no colostomy" and "no leg amputation". I don't know what kind of experiences she was basing this on.
Sure enough -- when she got old: nursing home and colostomy. I was able to stave off the nursing home 'cause she didn't live long enough. She did have the colostomy (what a horror show -- medical malpractice).
All that you can do is the best that you can do. I always figure that someone that's probably not going to be around that much longer deserves the good treatment NOW rather than the regrets LATER. But, you can't drive yourself to absolute exhaustion. Make sure that you take care of yourself too, *N*. To quote a often-used Dr. Phil remark: "Don't drive yourself into a ditch"
BIG HUGS (and love).
Barb