I may be new to this board...and I have not read your story. But I'm not new to divorce...having been thru a very nasty divorce and then a nasty custody battle.
Get a lawyer...there are protections and systems that are there to serve both parties. Your lawyer will know the next move...and will be able to protect you legally.
Ask friends, family, co-workers to recommend a lawyer. Don't go for the cheapest lawyer...find one with the most experience you can afford.
If you have any joint accounts...close them. Don't spend on them...or withdraw from them...just close them to prevent her from taking. Don't think "she'd never do that"...she will. My XW got a boob job on our credit card while we were going thru divorce. I call them "Mastercard and Visa"...paid for them, never got to play with them!
While you are waiting for your meeting with a lawyer...go thru her affidavit line by line and write your response. Find any documents or items that go against what she has stated. Gather all your financial info...tax returns, bank accounts, credit card statements, mortgage, etc. You lawyer will need all of that.
Do NOT involve your children.
Do NOT respond to her in any way.
Take a deep breathe and get to work. The more documents, statement, info you have on paper when you meet your lawyer, the better. Makes it easier for you to respond legally quicker. As another poster said...look at this now as a business item. Do the work to protect your self, your finances, your kids. Now is not the time for any pity party (not saying you are)...it's time to get pissed and use that energy to fight back legally.
You will be ok...you will get thru this and come out the other side! Best of luck!