hi . .. i am so sorry you are going through this - it's such a painful situation hon.

first, i would ask if you've brought up the possibility of couples counseling with your wife. from my personal experience, this will only work if both people are interested in making things work in the marriage. ((however, if you read some material on the internet, written BY couples counselors, therapy can be effective even if only one party is interested in staying in the marriage)) so it may be a good idea to persuade her to go to a couples counselor, if she will.
since she in a helping profession, she may already understand the benefits of a good therapist/counselor, so you may have good luck in getting her to go.

and. . . . even if she won't go - i would suggest you go alone. you need some support in dealing with this very difficult situation, and you're already suffering, it appears, with some PTSD and you're in a hugely tough place in your personal life, aside from your marriage problems.

a counselor could also help address the best ways to get past an affair - you are right to ask for her to cut off all contact with the man she was seeing, and it's possible she could ask for a job transfer or a change in schedule so that she could avoid crossing paths with this man. but a third party could help the two of you talk without the heated emotion - instead cutting through to the task of what to do, to get over the affair.

just a thought - perhaps your wife is not choosing her job over you, perhaps she is afraid of not finding a job that is as good, in our present economical condition, perhaps it is a comfort zone for her; starting over is really difficult. and it is possible that she is sincere, but wants her life to go back to the way it was - before the affair - unchanged.

this is probably not possible. that is why i think you both (or at least just you) definitely need to see a good marriage counselor, because this is one of the toughest tests for a marriage
i wish you the best hon . . .