Any eldest child with the biggest responsibilities in here? You still okay? How do you deal?

I am both the eldest and not the eldest. I'm the eldest of my father, but my step mother has three older children. Of those, the eldest is disabled (brain damage from a car accident) the next eldest is not very responsible (folks ended up raising his kids), the next one is out of state, I'm out of state, and my little brother also isn't very reliable.

Fortunately the folks have largely been able to manage. I'm fairly physically disabled, so I'm not able to help much there. But I have the highest income and help with their bills every now and then though my father's pride makes it hard for him to tell me when he needs it.