My condolences, but maybe you can find a little comfort in knowing this is as it should be.
I've just spent the last week comforting my uncle who just lost his son.
As sad as it is, a son burying his father is part of the proper march of life (not so much the other way around).
Cherish his memory.
Don't know if you have kids of your own, but if so honour your dad by being to them everything you loved in him.
Peace.