I am a firm believer that it's ok to be angry when you have been "done wrong" Jesus could turn the other cheek "becuase he was Jesus" !
I have to work through my pain and anger, I don't have a timetable, some things I have forgiven rapidly, some things still set me off 30 years after the happened.
My wife reminds me that it's called spiritual practice because just like anything else we cannot be good at it without regular practice.
So stew about it for awhile and remember that it's his loss, you will pick yourself up, dust yourself off and come back better and stronger, a new year is just around the corner, don't make a resoultion, find a new path to walk down.
Best of luck to you,
Bill