As well it should.
It's been 5 years since I learned that the man I'd loved and trusted for two decades had a secret girlfriend for 12 years.
I don't think of that very often -- I've moved on -- but when I do think about Mark I'm still angry at him.
And yes, therapy helped me move on.
But my feeling is that if you can mourn the loss of a loved one who has died, even years later, it's just fine, even years later, to feel angry at somebody who fucked up your life.
I'm glad that Medium put your essay in my feed today!