I don't know if I can say anything to create a shift in attitude with regard to specific resentments. I know they logically seem so right to the person who has them. A job is so closely tied to self-esteem as well.
In the past, I used to think of forgiveness as "disarming" the person who caused harm. It makes sense to see an absense of resentment as a freedom. And if I can't be perfect at something, I can at least act and think in a way that amounts to progress.