No one is here to attack you, and this IS a safe place to vent. I fear sometimes people get frustrated watching you (or anyone else) make the same mistakes they have made over and over again to predictable results. I see you are starting to get it, and I also see that you don't want to get it, because you are holding onto the belief that you can pursue her back into loving you.
There is a world of difference between dealing with someone in a marital argument who is mad at you, but who is still deep down committed to the marriage, and someone who is simply "done" and already checked out. Everything that you want to do would work in the first case, and nothing you want to do would work in the second case.
The difference between those two states is hard to grasp, but it is a crucial difference.
I'm glad you didn't write any letters to your wife's family. Even if she is batshit crazy and making the worst decision of her life, that is still HER family, and she needs them for support. You must resist every temptation to try to go around her and enlist her family's support. If they've known you for 30 years, they already know you and nothing you tell them now is going to make a difference.
Don't do anything to help your wife separate, make her do all the work. Splitting up your bank accounts already was a mistake. Follow the lawyer's advice and don't put the cart before the horse. The first step is that she should file. Until she does, you should maintain the status quo. DB'ing is not about placating her, it's about not pursuing her.
You can say "no" as often as you would like, and you will not be jeopardizing your chance of reconciliation at all. Protect yourself and protect your kids, let her do what she's going to do. That's ALL you can do.
Acc
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
