I know that feeling as each time I leave my mom I wonder if she will be there when I return, she is 90, has macular degeneration pretty bad, other then that I know shes going to go someday sooner then later, Like you Ive always felt my Mom would be around forever but that day is creeping forward and I do hate to go off and leave her. I think someday in the next year a decision will have to be made as youve done, but ENJOY your Dad as long as you can, I lost mine when I was 18, My Mom has been the rock of our family for many many years. Waiting for that dreaded day seems unfair but the realization it will happen and accepting it is part of growing up, growing older.
I wish you well with your Dad and cherish every moment, EVERY MOMENT...