Before the two of you make the change, it would be worth trying to see if he would agree to see a marital counselor. He is holding onto the past and having placed the marriage on hold for such a long time.
If he does not want to work on the issues and you believe he is set on leaving, then it would be appropriate that you stop doing the wifely duties for him.
As far as what to feel, he's already alienated you from himself. You may try to find some way to cope with that should he remain unwilling to seek help. Otherwise it is as though you're relying on him to feel better. Speak to him about what sort of future is there going to be for your daughters, does he want them to learn to be unforgiving and give up on their family when things get tough.
In the mean time you set some limits with him. If he does not want to go to counseling, then there may be some in home self help tools to use (couple's workbooks/programs) but he must be willing. Tell him that he is giving you mixed signals and that you do not appreciate living in a limbo all of this time. Absolutely no begging because he has been punishing you with his behavior for what you did years ago. It is best to approach this situation rationally (hopefully he has some rationality left in him)
As far as moving on, you have to feel comfortable with your decision. Look at the pros and cons, mentally project what the future will look like should you do this or that and where would the girls fall into that decision. You could use some individual counseling just to let you sort your feelings and make some short term plans even if he does not want to go to counseling. If you have EAP benefits through you job, you may be entitled to some free counseling sessions.
The Couple's Survival Workbook: What You Can Do to Reconnect with Your Partner and Make Your Marriage Work by David C. Olsen and Douglas Stephens (Paperback - Oct 10, 2001)