Here is something I wrote in the past that i think speaks to "what keeps me going"
When I first started going to my clinic visits they would always ask if I was "depressed". And I would always give them the same answer "of course I am, I have a terminal disease, I watch my body die daily, I watch my loved ones suffer, and this illness screws with my emotions, what the he11 do you expect". That of course lead them to try and "force" me to take anti depressants (please note that I do not judge people who do want them I just don't) etc..
In my opinion they were asking the wrong question. The right question is "what do you want to to with rest of your days and how do you want to be remembered?" For me the answer is that I want to love my family and be remembered for doing so. For me "to love" means to count them as more important than myself. So even though I am so dependent upon my wife for everything I try not to complain, not to upset her, not to ask her for things unless I have no choice, to help by ordering groceries on line, to help her with her work by offering any support I can think of. When I am asked by any one how I am doing I reply by asking how they are.
This takes a lot of effort and a lot of reminding myself of who I want to be, because it is so easy to feel sorry for myself. This illness sucks. In so many ways it seems unfair, and I am sorry for all the losses you are going through and will continue to go through. I use this forum to ask questions and whine at times, but I try to always put those nearest to me first. When the dark thoughts come I remind myself of who I want to be and what I want to be rememberd for. Those thoughts are not consistent with what I want, to let them win is to loose against this nightmare.