I suppose this is irony but to me it's a matter of knowing yourself and wishing to maintain your integrity. I doubt that you see your choice as transactional, a matter of "I'll do this for you if you'll do that for me". More likely, like me you saw a job that needed doing and that nobody else would do. My sibs wouldn't lift a finger (unless there was a lot of estate money on the table) to help Dad and Pat. I would have hated myself if I just turned my back and let him feel abandoned, and given that I literally owed him my life the choice seemed clear.

I'm hoping that you have some resources to draw on so that you can get some respite from the 24/7 nature of caregiving. It's hard for people who haven't done the job to understand the stresses involved, even when the actual daily tasks aren't that difficult. I finally had to get into counseling, my health, mental and physical, was suffering. She helped me to break free of the guilt I was putting on myself, to finally after 5 years place him in assisted living. She helped me to understand that HE made choices that led him to his predicament, that he chose to dump his responsibilities on me, and that I had the right to accept as much of them as I wanted to and to say enough when I needed to.

Take care of yourself, lean on your friends, don't let yourself feel guilty for not doing everything "right".