Sorry for you loss. It sounds like you did excatly what you should. Be there by his side. It is up to the patient, with the doctor to decide what treatment to persue, and sound like your dad was more than capable of that. You were there to support him and give him comfort. You should be proud of how you held on through extremely tough times! And now coming out on the other side, do not be afraid to talk about it. Your feelings are valid.

Hope you heal well my friend! Live long and prosper.