I'm in a platonic relationship with a man 15 years older than myself. He's 80.

We have been together for 16 years, no marriage due to financial issues.

My question is: I am considering leaving this man to carry-on with my own life. But, he has health issues, Chronic Pain, Diabetes, Obesity, Smoker, etc.
He doesn't drive anymore because I drive him anywhere he needs to go.
He seems to me, to be giving up on life. His feet turned black and he refused to get medical help. I spent 3 hours trying to convince him that he needed to go to the E.R., at his nurses and Doctors' request.

Now, this is a HUGE ethical/moral issue, for me. Do I owe it to him to stay with him until he dies? I have health issues (too), that is causing me to have my own issues to deal with. The disabled helping the disabled. This is a very difficult situation to be in. He can barely walk and really doesn't do "anything", to help himself.

Is it wrong (of me), to give up on this man?

What about my need to move on?

Any ideas would be greatly appreciated.