My mother died on January 7th, 1996, just days after her 72nd birthday (12/30/95). It seemed too soon for me, then 47, and even more so now as I approach 72.
Saturday January 6th, 1996 my mother was again back in the hospital, 18 miles away, with pneumonia. I had planned on visiting her but I was fighting a bad cold and the SF 49ers was playing Green Bay in a NFL divisional playoff game. SF lost 17-27. I was going to visit my mother the next day, Sunday January 7th, if I felt better or on Monday. My mother died before I could visit her again. I have felt guilty ever since even as I know my visit would not have stopped her dying.
Dad died May 1st, 1998 of a heart attack while mowing the lawn with a push mower. I curse him for not paying someone to mow, ask me (I would have hired) or at least buy a gas lawn mower. I was out of town when he died. I have felt guilty for not advocating better ways for mowing while he lived. I knew, short of my buying the lawn mower and perhaps not even then; my dad was going to be cheap (scotch thrifty) and stubborn.
Guilt is something many of us have for different reasons. Not all guilt is justified or warranted. I will pass on any judgement of the above, and guilt still exists.
May you have resolution for any guilt that bothers you. Past events cannot be undone.