DM, I understand what you're saying. You CAN stand up for yourself, but not in a way that tries to make her do or not do things. Read about "boundary setting", and I also recommend the book "Hold Onto Your N.U.T.S.". You want to decide what is important to you -- how will you live your life, how will you allow yourself to be treated? Take it down to your core principles that you feel allow you to live with integrity.
If someone violates your boundaries, then you stand up for yourself. It takes some time to get your head around. If someone is yelling at you disrespectfully, saying "You can't talk like that!" is telling them what they can and cannot do. You can't enforce that, you can't control them. Saying "I will not be spoken to like that" is about what YOU will do, it's about what you will and will not tolerate. They can continue to rail and tantrum, but you're not going to stand there and listen to it, you're leaving. That's how it works, it has to be phrased in terms of what you will tolerate, and what you will not. How you will treat people, how you will treat yourself.
Now is not the time to pick fights with W, she wants space from you -- give it to her. As unbidden says, leave her to her journey. Unbidden gave you some great advice.
The typical example of this is a wife who complained that you didn't pay enough attention to her. Now, when you're the LBS, you think you should 180 that and start lavishing her with attention. Unfortunately, that's one complaint that you should NOT 180 right now. Instead, you need to demonstrate that you're capable of paying more attention to her by being more compassionate in general, spending more time with the kids, etc., but you can't do it with her because that is pursuing and pursuing makes a WAS run.
--Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015