I think that even if we are with someone, going through D is a grieving process as we have spend a good number of years with H. Don't be too hard on yourself.
One thing I'm learning the hard way is actions are louder than words. Look at what the new person is prepared to do for you. You are closing a chapter of your life to start a new one, embrace it and live day by day.

(((((Hugs)))))))