I have similar frustrations with my father and siblings.
Serenity to accept the things I can't change
Courage to change the things I can
Wisdom to know the difference
I've been working everyday to find that wisdom. It doesn't come instantly. I also wish sometimes that I could sit with my father, talk about my sobriety, and he would, all of a sudden, decide that he wants to be sober too. Life just isn't magical like that - that is, I don't have that kind of power. I can't lift my father's disease away - Heck, I can't lift my own. I'm constantly seeking the higher power to help me out with it (go to meetings, talk to other sober people, attend counseling).
I can set boundaries and make choices in my own life but I can't make choices for other people. I can't coerce my father into seeking a doctor, going to counseling, attending 12-step meetings, etc. I can only do that for myself. I can seek help for me in dealing with the painful experience of watching my loved ones die. Can I stop the world's pain? Like tsunami's and earthquakes and murders and etc? Nope. Yet, when it's so close to home and in front of my face - I so wish that I could. But I can't - I don't have the power to do it.
Letting go of the possibility that I could FIX the problem in such a bad-a** way (like in the movies) is a DAILY struggle for me. I put the focus on myself in figuring out - how do I cope with this? how do I live a happy life? how do I maintain my own sobriety?
One day at a time.
Have you considered 12-step meetings? such as Al-Anon? Just hearing other people's stories helped me personally quite a bit. This forum has been awesome as well.
Best of luck!