Leo, I KNOW you. I don't know anyone else who does everything that can be done and more, when there is need. If there are things you wish you had done, and did not do-- I bet if you look back at the day and time you thought each of those "shoulds", you'd see someone going 200% or more beyond the time and energy required, loving SOMEONE who really needed it right then.
If were were all to confess those thing we had not done, that we know we ought to have done-- if we heard each other's failures-- you'd see that we all do the best we can, and that each thing we regret becomes a spur to do something the ext time around. ANd that's how a life is lived-- building upon one life lesson to get to the next.