There are definitely stages, shock, denial, anger, acceptance. I tend to have one of each every day, but the amount of acceptance is growing.
Someone shared with me a metaphor during my divorce which I found helpful, so who knows, maybe it will help you as well:
Imagine your house being destroyed by a natural disaster. It sucks, you have to start over, and you have to cope with a lot of loss. Eventually, you get to the point where you're ready to build a new house. Only this time, you get to pick out what the new house looks like. You get to pick the decorations, the color of the paint, the fixtures, etc. It may not seem like it when you're in the immediate aftermath of the house being destroyed, but eventually, you build a house that is exactly the way you wanted/needed it, and maybe wouldn't have done otherwise if not for the natural disaster. It took hard work, pain, and perseverance, but you ended up even better than where you started. No one else did it for you. You made that happen.
What I'd like to tell you is, things will eventually get better.
What you're describing happened to me but more at like T+nine-months. I had supported my wife for a decade and caught her cheating. That's, normal. Sadly.
Despite being my daughters primary caregiver, i wasn't able to see her for about 5 months due to the inequity of the court system. It was terrible, but I got through it, and she and I have a wonderful relationship now.
Play the long game, worry about your welfare and your daughters first.
And if you need advice or would like to talk, indicate so and I'll get you my contact info.
What happened afterwards is omitted for legal reasons.
It has been the worst two weeks of my life. We have not spoken since the day they left and I have not seen my daughter.
I should note that it takes two to tango. I could have done more to prevent it from happening. I could have done a lot better, but I just didn’t realize the fragility of our situation.
I cannot wait to hold my daughter again.