Respectfully request advice as newly divorced dad

Sorry to read this.

As has been suggested, "lawyer up", but I also give this advice... Strike first with the divorce. Don't wait for her to do it. Don't say a word to her about it, just do it and do it tomorrow. Been there, done that, and it worked.

So many guys wait for it to happen rather than take the offense. In the legal world, the first one to file often has the upper hand.
Also to add to this; "She" has been planning this for some time, but this is all news to you, take the advise above and get that Lawyer now! Look out for You first from here on.