I am glad you have booked an appointment with an attorney. I would not wait until Friday - I would keep calling around until I had one who could see me sooner. Most of them offer the first 30 minute free. You need to know where you stand legally.
My suggestion to not engage was based on your emotions probably being all over the place and the likelihood of things being said that you will later regret. You sound in a better place now - though I would keep correspondence to text - that way you can draft a response, leave it for a bit, and then re-read it to make sure that you have not said anything that could be misconstrued (or used against you later). I would avoid phone conversations.
My 2cents regarding your daughter.
Break the NC. I would send a simple non accusatory text "Just wondering if you have a date yet for the operation?". If she doesn't come back with anything, resend the text the next day until she does. If she comes back, and the text is full of hate, ignore the hate. This is not about you, it is not about your W. "Ok. But do you have a date for the operation?". If/when she gives you the date simply say "Thank you" and maybe suggest (if you want to) that you would like to be there.
She is keeping you away from your children. Keep calm. Ignore anything and everything that is said that isn't directly about the welfare of your children.
If it were me I would ignore any verbal communication (phone or otherwise). I would not be able to stop myself from rising to the bait, or telling one or two home truths of my own and now is not the time for hot headed conversations.
