However, I CAN NOT afford to keep our house and rent an apartment.
What are the financial ramifications of divorce in your situation? Does she work? Would you have to pay alimony?
If you tell her she's not welcome to come back if she goes to OM, SHE is the one who has to figure out how to afford an apartment, isn't she?
She's still in Fantasyland, and I think if you don't give her a dose of reality, she likely will continue with this OM or move on to another one.
But you need to be strong, gentle, not bitter and angry. Just enforce a reasonable boundary (and btw, it's an ENTIRELY reasonable boundary to say "you cannot return here if you choose to go continue your affair".).
You've had a chance while she was still here to show her the best that you can be, and should keep doing that. But I don't know any woman that would respect a man who said "sure, honey, go off and sleep with your OM and I'll still be here when you get back." You have to be willing to let go of the relationship; so long as you're still pulling at her, she will pull away - but if you let go, she might just come back.
Just tell her - "look, I love you, I'm willing to do what it takes to repair this marriage, but if you still choose to go with OM, I am done. Don't come home."
You know how to establish boundaries with your kids, don't you? If your teenager said they wanted to go get high on heroin one last time, would you let them?
