A monkey branching tale as old as time…

Crosspost "Divorce Story" from /r/Divorce:

The week of Thanksgiving of 2021 my wife decided to separate. After a week she decided she wanted to get back together. Then in early January she decided she couldn't do this anymore. Several days later she told me she wanted a divorce and wanted me to sleep elsewhere. I asked for marriage counseling and she refused (which she has several other times during our marriage). The following day she came up with a schedule for the kids (we have three) for which nights they would stay with me and her. She told me she wasn't going to file yet and she was still going to try. At that point she admitted she might be interested in someone else. The following Monday she said she wanted a divorce again. The next day she said she was willing to try but she also had to see where things went with this new guy. I then found out through another source that when I had the kids away from our home she was having this new guy come over. After several weeks of this she finally decided divorce was "the best option for her". She told me she loves me but isn't in love with me. That she didn't want this anymore and it was unfixable. She told me she deserved to be with someone who makes her happy, not someone she has to fake being happy with. Due to scheduling I have now moved back into our marital home and she got an apartment in mid February. That same week she started bringing this new guy around our kids without my knowledge and asked our oldest to not say anything to me. He's now over there pretty much 24/7 even when the kids are there and spending the night. Our oldest refuses to go over because she's so mad at her mother. My "wife" has since quit her main job and is working at a worse place for less money, her new boyfriend lives at home with his mom after he moved states away from his own children while working part time jobs. But she tells me he makes her happy and she thinks she loves him. I've been marred with depression for these past few months and it's eating away at me. I feel like I should be furious at her but all I can feel is sadness and guilt for not being able to make her happy. I'm still stuck on her and being unable to let her go... She will still tell me that maybe sometime in the future when we worked on ourselves maybe we'll find each other again. I want to move on and let her go but all I see is her and cannot envision a future without her. I've been going to therapy but it doesn't seem to be enough. I struggle to get through every day... We've been together for 13 years and married for nine and it feels like she just gave up on us because I couldn't change.