Coming from someone who had just about the worst goodbye possible with their Dad, that I had to bitterly relive today (which practically immobilized me playing in my baseball games and tonight), it's a blessing that there will be plenty of healthy positive memories and peace. You were able to have a coherent and positive talk, spend time, and have a nice memory about the good old days. It's virtually perfect from my eyes. Losing a loved one is terribly hard, but when that time comes, accepting it and moving forward in a healthy way will certainly be possible because of the terms of the relationship you've maintained over all of these years.

With your Mom, that was really bad luck, but relations were seemingly good and there were no hard feelings between you. There's really nothing to blame yourself for because it wasn't like you deliberately neglected her. It was just a fluke (if that helps) and she knows you wanted to be there for her.