Read Sandi's 37 rules. Then read them again. And again.
Couple things:
1. Stop with the love notes. This falls into the "do not beg, plead, etc." rule. Also, in general, now is a good time to avoid anything in writing. If you feel any urge to pour your heart out in writing to your W, don't. I can't emphasize this enough.
2. Give her the space she asked for. You aren't going to nice her back right now. You're going to feel impatient. This is going to be hard. Buckle down and weather the storm and take all pressure off. No R conversations. No asking her to clarify if she wants to work on the marriage.
3. Keep working on you. It's great you are in IC (hopefully with COVID you are still able to go or at least attend video sessions). Do this for you. Don't make a show of your improvements.
Most importantly, look at this as an opportunity, a gift, for you to get a handle on your mental health. Whatever happens in your MR, you have an incredible opportunity to transform your life and become a happier, healthier, person.
She's been married to you for 23 years. She thinks she knows you. She's going to think any changes you make are temporary and won't stick. It's going to take time to turn things around. Keep focusing on yourself. You can do this.