A week ago, you might have been surprised at how often we see SAHDs who got cheated on. Today, I think you'll be less surprised. It's really not too much different than what we see with SAHMs. The dynamics are the same. The cheater undervalues the SAH partner and doesn't believe they have options. But, just like I wouldn't tell a SAHM that she has to tolerate an unfaithful spouse, I'm not going to recommend that to you either.
See an attorney. Find out what your rights and her responsibilities are. You don't have to file if you're not ready, but you do need to get a realistic picture of what your situation is. Cheating husbands can't just put their wives out or refuse to pay child support or spousal support... and neither can your WW do those things. You do have legal rights.
Now, is your life going to have to change? Yeah, I think you'd be wise to get some job training and get back into the job market. This is the same advice I would give to a SAHM in your situation. Your spouse has just PROVED to you that she can't be counted upon to do the right thing. Believe it. From this point on, you don't want to be in a position where you're forced to rely on her. That said, don't go rushing off to take some hamburger-flipping gig. If your WW decided to end the marriage today, she's paying you alimony. Get some legal advice so you can get positioned for a job which pays you well enough to live.
Next... boundaries. Boundaries are for you, not rules set out for a grown ass woman. So frame your boundaries as "I will" or "I won't", ie. "I will not tolerate living with a spouse who cheats on me or is in contact with her AP". Let your WW know that you're not tolerating it. If she wants her family, she's going to drop the AP. Otherwise, you're filing for divorce and full custody of the children with a morality clause to keep her paramour away from them. If she wants a boyfriend, there's the door and she shouldn't let it hit her in the ass, but she's not going to keep you as a husband and have a boyfriend on the side. Mean it. We don't put out ultimatums that we're not willing to enforce.
Frankly, it's going to be some time before you really know what you want. There's a chance that even if your WW turns into the model, remorseful WS, you won't want her anymore. Bide your time, to the extent you are able. This doesn't mean ignoring boundary-busters like contact with the AP. But it might mean pretending more tolerance for her presence than you actually feel. Ultimately, you want to get into a position where if your feelings for her change and you find you don't want her anymore, you can leave the marriage.
As far as all those freaks who knew and supported her in her deceit, take the high road. I know it would be super-satisfying to call each of them up and give them an earful, but you don't know how this thing is going to play out yet. If you end up in R, you don't want them undermining. Better that they feel a bit guilty about their behavior than defiant and plotting. Over the course of R (or D) you can distance them. They're a problem for later days.
Remember that in order for R to work, the betrayed spouse MUST gain the upper hand. This is one of those rare situations in which equality in partnership is actually a one-down. It's kind of like dogs living in a pack... your WW needs to show her underbelly and recognize you as leader. It's an unkind analogy when applied to people, but in terms of healing, it's apt. Your WW drove the bus into the ditch. She's got no business behind the wheel just now.
Cheating is ALWAYS about the cheater. It's not about you or anything you did or didn't do. It's about a hole in your WW's character. And that might be something you've never noticed before, but it's always been there. There's something inside her which is capable of saying "yes" to sustained perfidy. And THAT's the something she needs to fix. You can't fix it for her. She's the only one who can. As BS's we have a tendency to want to blame ourselves. But that's just a subconscious control mechanism, ie. if it's about us, we can change or fix it. We can't change or fix this because we didn't cause it and we can't control other people. So, let all that angst go. It's just a distraction. Concentrate on what you need to do in order to achieve the one-up. That's your center of power and where you'll find CHOICES.
I know all of this is very confusing, as new to betrayal as you are today. Read as much as you can in the Healing Library and I've got two book titles for you to read first: How to Help Your Spouse Heal from Your Affair, by Linda McDonald will help you identify the remorse of "successful rebuilders". And Not Just Friends by Shirley Glass will help you with boundaries. A cheater's boundaries are insufficient, and Glass does an excellent job helping us define and reinforce them.
Strength to you. I know it doesn't feel like it today, but you WILL get through this.
[This message edited by ChamomileTea at 1:14 PM, May 13th (Wednesday)]