Coming to a head

It's getting increasingly more difficult to maintain my composure around Bridget. I don't mean to be snippy, but I just can't seem to help it. It just comes out.
Why not though?
2 weeks after our 2nd daughter was born, in January, she started treating me like shit and hasn't stopped.
She had a 2 month affair with one guy, random sex with another, and is now involved with, whom she calls "the perfect guy for her" with NO concern for my feelings. No consideration. Nothing. Except some ridiculous expectation that I should just be cool with the situation.
I can't. I won't.

It's over!
She needs to go and plans to.
She's been with him for a month, and now, tonight, tells me she's moving in with him in a few weeks.
Yay, she's gone, but this just makes everything worse. Now my kids have a different adult male in their daily lives. My family is shattered and for what? Because this 30 year old teenager has no sense of loyalty to anyone but herself and everyone else has to suffer.

And it's not like they're teenagers. My oldest daughter is three. Do you remember being three? Probably not, so she'll forget that I put her to bed every night. My baby will never know.
Now someone else will be doing that. The first person they see in the morning and the last they see at night. How can she just take this away from me, so nonchalantly?
And on top of that, like a prison sentence, I'm trapped in this town now. I'm going to be in this fucking town for the rest of my life because of her selfishness. Staying here was never the plan.
I cannot leave as long as my kids are here and this is not my home. This is not where I want to be. Peoria is alright and I've met some cool people, but it's not home. And I've been miserable and broke since the day I got here.
Don't I get some say in this? Don't I have any fucking rights?
Pardon me if I think that having babies means the rockstar dream is over.
Pardon me if I feel like the family is the most important thing you can commit to.

I hate her.
I've said many times, I have not been perfect. I have issues, but instead of standing by me while I work through them, she acts like she HAS been perfect.
Oh, she'll admit to her mistakes but takes zero accountability for them.
Instead, she makes it all seem like it's all my fault. Probably how she justifies it to herself.
She has shit on me in the worst ways for the last 6 months, and I'm the one to blame?
Fuck that. I have no clue where to turn now.