As things keep going wrong with mom, my ability to cope goes away. The thing is, it doesn't matter if I can cope or not. I have to. I can't change it. So it's like... falling, and hitting a floor. You take a deep breath, say to yourself, "This is as low as I can go. Okay. I can handle it."
And then the floor breaks, and you fall down to another one, and you say to yourself, "Okay, I can handle it...."
And after a while, it doesn't matter if you can handle it or not. You keep falling anyway, so you have to just get on with life as best you can.