There's no sense in getting madder at him each time you think about it. You might want to try to find a way to forgive him or at least let go of some of your own anger at his choices. It really can eat you from the inside.

Kudos to you for looking out for your mother. I'm the sole person who can look after my own and I only hope I have the strength to support her when the time comes.

It sounds like both of you could benefit from grief counseling, even this long after the fact.