Newbie Error- LRT too Soon- help!

[Bart42]

Thanks for the whack on the head. So I've got a WAW who has written off our marriage. Learning something new each day- I know I've been slow to follow the advice here, but I'd be grateful if you all could please help me get back on track and understand my options.

To answer your Q, OM is a 30 year old numnutz with little financial future- he is a party boy. W makes six figures a year- she doesn't need him financially.

So back to me:

A going on for almost a year; known to me for 3.5 months
During 3.5 months I fix much of what W saw wrong with me, but she notices, but is too far gone to care.
Even though I fix historical shortcomings, I still plead, mope and cry for a solid 3 months of this time.
W continues to disrespect me and our marriage- she has no problem continuing A and lying.
I only GAL and DB starting two weeks ago.
I don't want to separate, I want to keep the family together and save my marriage.

So what are my options? Telling her to stop it useless. Moving out myself is unacceptable for the picture it paints to my children. Telling her "stop it or move out" will result in status quo. Everyone says going dark is very hard with kids.

So what do I do? How the #%^* can I set a boundary where the threat isn't me moving out or filing for a D I don't want? Seems my only option starsky's original advice of the After the LR technique? Any modifications suggested given the history I've posted? Seems I've got to say "I told you I wanted to save our marriage but was unable to do that with OM in the picture. I gave you the time you asked for to think. You used it to sign up for a dating service so I have your answer. I suggest you get a lawyer as mine will be contacting you." Is this really my only hope??????