JW -
Your affair remaining secret has sabotaged you in so many ways.
1) it has kept you in this in between space.
2) it has kept your husband blind to what the REAL issues were in your marriage. Keeping him from doing what he needed to make himself whole. Most likely making him feel broken and defeated.
3) Your husband was unknowingly in the presence and potentially influence of your AP... in an environment where he could receive daily feed back from your AP, people the AP influenced, or the AP's work friends that was/is designed to influence you husbands opinion of you and or your marriage.
4) when you HAD your chance to reconcile, your husband had no clue he had competition.
5) keeping this secret has kept you from being the woman he fell in love with for so long... that "YOU" is most likely dead and gone and this secret keeping, lying, cheating, mattress-back that stairs back at you in the mirror (as you wipe away the tear from mourning your marriage) is the "YOU" that has taken her place. and the old "YOU" can never live again as long as you keep the your affair secret from him.
6) you have kept this secret so long and with deception to such an extent that you probably don't even know who you are; but the man who loved you, with all his heart, and made 3 perfect little people with you sure as hell has no clue who you are....
Its true, if you tell him he may hate you. But if you don't tell him, he will never really know what happened to your marriage & why it failed. And he will never be able to truly love you again.
Out of curiosity do you really love him and miss him? I ask that not to be my usual shitty self, but to point out a few things...
If you truly love him, wouldn't it have hit you when he moved out????
If you truly love him, wouldn't it have hit you when he filed for divorce????
If you truly love him, wouldn't it have hit you when he met someone new????
Why did it only hit you once the divorce was final??? I have a theory.... Something snapped in your life ~2+yrs ago and you became much more emotionally immature & still are... here is what i mean, like many young women (teens-mid 20's) you seem to want what you "can't have". except its no longer the bad boy or the guy the parents hate, or even your married English professor now it shit that has REALLY FUCKED UP your life. here is what i mean...
Affair is the forbidden fruit.... you want it you bite that apple.
Only its not dangerous enough it has to be something so close and so "In-Your-Face" to your husband... but its your secret...
Your husband move out, but.... Hey, he's still your husband, and besides you still see him..
Divorce is filed... hey you both decided it was best, but you can back out anytime .... right...
But now he is getting along well with out you, has a SO, now you start to realize you might not be able to have him anymore... so you start to be nicer to him, show him more caring and affection... just to see if you can still have him.
Now he takes your bait and wants to work on your marriage, you jump in just to make sure he is serious... then you realize you can have him so you and your secrets Sabotage the R.
Its all taken so long you never realized how close to the end you really were.....
Hell, the divorce was taking so long you probably only wanted it because you thought you couldn't have it. you even stopped going to the court house with him.
Then 2 weeks ago he calls you to tell you the divorce is final... and you realize... "YOU CAN'T HAVE HIM, ANYMORE"
Then you realize you CAN have AP, and so just over a week ago you break up with him.
Only light and time can fix what you have destroyed. You must shine a light on what you did, what you hid. It will take plenty of time for that sting to go away (if ever). Then take time to heal yourself. And make no mistake, you are broken, otherwise you would not have cheated and deceived in the vile way you have.
Lastly, you said/imply that your husband must know and be in denial... and you might be right but here are a few thoughts...
1) with the AP being a co-worker of BH (unknowingly to him), odds are that bug was put into his head (just not who) in order to blow-up your marriage.
2) if he did know and was in denial, then he tried to save your marriage and R, so what do you think that says about how much he lovED you??... unfortunately for you, that's a love you can't have anymore!!
Just my shitty thoughts!