Solid advice DnJ. I will add that you need to beware of niceness. It's only in her favor. As you can see, you waited until the next morning to respond and the, boom, 1.5 hours later came the punchline. She's not going to suddenly change and start being consistently nice without needing something in return. DnJ said it best. Take time when responding. Anything that can be spun into you agreeing will be her ammo in mediation. Especially if in written form. It is so hard to wrap your head around right now but it's the truth. She is out for herself, period. From the get go, my father told me "she wants nothing to do with you." I didn't digest this for months, but it was/is true. Please don't take this as us ganging up on you, or that you did something wrong. We are here to help and you must absolutely protect you and your kids. As a general rule, if you're on the fence about something, take some time. Hang in there.
