((LMo))
This is definitely a time when family relationships go crazy. I agree a good heart-to-heart with your brother maybe along with your stepmother might give you some relief from the situation. Can you talk to him about what your feeling without getting in an argument. Maybe acknowledge the great job he is doing; but that you also want/need to help. Let him know how important it is for everyone to feel like they are contributing and getting a chance to comfort your dad. Let him know that allowing you or your stepmother to provide him with care does not diminish the impact of his compassion and care. By working together you all can support each other. It will allow him some much needed time away to rejuvenate so you all can work together to provide the best care possible. Just some ideas.

As for the expectations your father had/has of you-- feeling like a disappointment or failure in his eyes sucks, been there done that, still doing it to myself 10 years later. Unfortunately parents like to live vicariously through their children and they don't realize the pressure they put on them. Not sure how to deal with this. When I get into this mode I try to remind myself of all the things I have achieved and do well. This helps a little.

Take care