Me and XW got married while she was in EA with OM. That felt real too
I was an ignorant idiot at the time (with regards to OM) , but it felt real and I still believe, though I don’t understand how, she felt that way too.

Read as much as you can. Be a rock for your Daughter!!!!!!!!
The advice given here already is gold.
Read it carefully and ask questions.
We may be harsh from time to time, but we are here to help.

Me: 34
Stbxw: 30
D:5 D:3
Mini bd: May/June 2019
Married: Aug 2019
BD: 6th Dec 2019
OM Confirmed: Feb 2020
March 2020: I filed for D
Waiting for D to be finalized and W to move out end of January 2021