I'm sorry you're going through this! This is not always practical, but what I found helped my D-day antiversary dates was to plan something to erase the bad memory of that day.
My worst trigger date for some reason was the day he met her. I planned a romantic getaway weekend at the beach for the 1 year mark of that date to create a NEW memory. I am now nearing the 2nd year of that date, AND I CANT EVEN REMEMBER WHAT DAY IT WAS! Hurray!! I know it was May, but the specifics have left me.
Do something special for yourselves! I know it's hard, but sometimes you have to force yourself instead of letting the bitterness win. Go out to dinner. Plan a trip for the upcoming D-day. Make new memories!
Good luck! Take care of yourself today.... AND the days ahead.