and I feel so weak for thinking about ending it, but I just want to move on ...not saying D for sure but
Yet, issuing an ultimatum or getting a divorce doesn't end anything really, nor does it have you move on. One truly ends it when they internally sufficiently disengage and have "fallen out of love" to a degree, have regained their center and are able to stand on their own confident feet again focussing on their own life and no longer obsessed with the WAS. It's not stating an ultimatum or filing a paper that accomplishes that.
The rollercoaster continues otherwise, even more bumpier because now having an issued an ultimatum adds its own particular consequences to the ride, filing for divorce and getting a divorce adds its own too. Not just when you do it, but in the time afterwards as well, in those times when your thoughts go back and forth thinking things like "Did I do the right thing?", "Should I have given it more time?", "What if...?"
I know this is where NYS chimes in and says you're not detaching and if you did it wouldn't bother you that she is with OM
Chime! It's not that it doesn't bother you, it's that you don't let it bother you, you process it differently instead. For example, instead of freaking out because you've found out that the two of them are going to Honolulu, you may say to yourself, "taking romantic trips together is something that couples, be they upright or not, do. It's to be expected. She's living her life, and that's what she chooses to do. I don't have to like it, I don't have to agree with it, but that's her choice, all the same. She's her own person, and it has nothing to do with me. There's nothing I can do about it, so I'm not going to give myself agita over this. Instead, let me think about me, not them, and what I want to do (not about the sitch but about activities concerning living your own life, putting the emphasis on you living your life)."
It's a path to "acceptance", which is where we need to end up or remain bitter, hurt. Reflect on how acceptance will help by lifting you out of the emotional turmoil, how that change will be for the better all around. Envision same time, next year, and ask, do I want to still be somewhere in the same emotional state then, or do I wish to have climbed out of it whole and stronger?
basically I told my W to either choose the OM, ruin her life and get out, OR stay with me and work it out! I blew up... told me to push her to be with the OM to find out what it would be like!
If I were of the opinion that my life with someone else would be better (even by virtue of the fact that by default it would be better if only because I'd no longer be in the relationship that felt was causing me pain), then that partner telling me to "go ahead and ruin your life" would only sound like sour grapes. How is it effective to vent like that?
"Pushing" someone out completely so that they can fully experience what they need to experience is not the best way to go about having them let the affair hit reality and see for themselves if the grass is greener. The aggressiveness and hostility of pushing will be remembered. The anger shown serves to justify the leaving partner's reasons for leaving.
Instead, you have the nonaggressive option of "backing off". When you back off and give space, the element of anger is no longer presented, so gone is the heaping of yet more fuel to the fire. The leaving spouse is free to experience the affair in daylight for all it's worth. In addition, by using a nonaggressive approach, one avoids creating a point of dissension for the WAS for them to battle against, IOW, one doesn't create yet something more for the WAS to use as part of their wall.
When you present an ultimatum, it presents an 'either or' choice, extremely limited choice with only two options, both of which imply a finality. Why put that into the WAS's mind... if only yesterday you really wished to 'save' the relationship? When you back off and give space, the WAS is still free to make choices, but finality is not implied. And you still have the ultimatum card to play down the line when and where it may work better in your favor. It may work better in your favor in time after some healing has been accomplished in both of you: the WAS's negative feelings may have dissipated, you may have provided consistent positives during that time that may have re-attracted the WAS favorably, the WAS may come out of the fog, see her grass wasn't necessarily greener, may have reflected on their part in the downfall of your relationship and realized that they were faulting you in error, have regrets... who knows? But then at that time, one would certainly have a better chance with ultimatums than at a time when all that's been happening is that the WAS doesn't want the relationship, wants to exit the relationship, is infatuated with someone else, thinks that they have an opportunity to experience a better life and wants to seize that opportunity, sees the primary relationship as all black, and has prepared herself for some time to be emotionally divorced from it, and sees the LBS as a person who spews and vents and rages and flip flops and pushes... all of which also seems needy and controlling and all in all, not a person one wishes to be in a relationship with.
When you issue an ultimatum, you must be at the point where you can accept however it comes down. If it does not come down in your favor, you need to be able to walk away. If you turn around after the decision has been rendered against you, you lose the ability to be equal in that relationship, for the WAS then sees you don't back up your words. You lose the ability also to be effective should you ever issue another ultimatum, the WAS will know that you don't mean it nor are able to back it up.
Being perfectly able to back it up means you establish equality in the relationship. You have equal power, IOW. The WAS does not have power over you, nor you her.
For when you surrender that power by not backing up the ultimatum, you effectively have given power over the relationship to the partner.
Back to choices, as a closing thought: many times, we see our options in an extremely limited view, typically, "I must do this or that". The reality is, there are several options very often. There is always the option to do nothing, for example. We "feel" we must do something at a certain moment, but that's just a feeling. For example, we may feel that "after considering tonight's events, I must say/do something about that tomorrow!" Why? Because we "feel" that a response is called for, we "feel" that we must do/say something to affect the circumstances in our favor. We're thinking with our emotions, however, not our heads.
These, BTW, are skills and views to be developed not just for this situation today, but useful in life and applicable to other situations as well, other relationships, be they employer/employee, parent/child, friend/friend, sibling/sibling, you/a stranger.