Married for almost 12 years. Have three young children. I am new and I don't know if you all find long rants annoying so sorry in advance if this is long.

I saw this coming for months. I'm not the guy she married and met years ago and I know this. We both have faults and are opposites in all the little ways but have the big things aligned, which I guess isn't enough. I got complacent for a while and when I noticed her distancing herself I started trying to improve but it was too late. She asked for a separation, refuses to use the word divorce. I was really calm at first but it could have gone better. She says she wants space and has started making arrangements for living situation and therapy for kids. I want to reconcile and be the man I was for her. Maybe I'm in denial but I get mixed signals from her. She wants space but still says I can stay home and will message me throughout the day. She just bought dresses for a wedding we are supposed to go to this Fall. Am I in denial and grasping at straws? We both know we have a big conversation coming very soon and I can't mess it up. I can't change her mind with words, she has too much pride in her decisions for that. There's always details missing but ask questions if you'd like. I'm blaming myself a lot here and feel terrible.

We have done therapy, she hates it.

TLDR, wife asked for separation but getting mixed signals maybe? Asking for space but still spending time around me and messaging me. How do I handle big upcoming 'talk' if my goal is reconciliation?