But I do think there are some nuances that I haven’t come across reading through some of the other threads so I thought I’d share my story to see if I can get any feedback or ideas.
I didn't really read anything that stuck out as being different about your sitch, unless you mean the nesting arrangement? That's not that unusual.
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During this time, especially the beginning, I took on most of the parenting duties. I already cooked all the meals, but now I was tasked with taking kids to soccer practices, events, doctor’s appointments, trips, etc. because she wasn’t able to do it. My love language being acts of service, I felt like I was 100% showing her how much I loved her because I did everything.
Ironically it was probably having the opposite effect and making you less attractive to her. All of those things are beta activities. Beta isn't a bad thing, but alpha is what women are attracted to. Beta is boring! Alpha is exciting. You've got to strike a balance between the two to keep the interest levels up. Like so many of us you went full beta thinking it was helpful to her. And it was, but she likely was no longer attracted to you as a man. You became a helpful roommate.
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She says it isn’t about wanting to be with him or anything like that, just that I wasn’t there for her and he was and since he was around back when she was going through some hard times, he could relate.
I would say she's being mostly honest there. It usually does start out that way, the WAS loses the emotional connection and seeks it elsewhere. However, that doesn't mean she JUST wanted someone to talk to. She may imply or even tell you that, but don't believe it. You are now Plan B and she is actively pursuing a Plan A. She will do things to keep you on as Plan B, like throw you a bone now and then, have sex or whatever. You'll likely find this confusing because you -think- those are positive signs. But right here and right now, she is full steam ahead on replacing you. The sooner you realize that and start acting accordingly, the better.
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The idea is to work on ourselves and see if we can figure things out.
That's just WAS script. Like Steve said, the REAL idea is to have a place to have sex with someone else.
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seeing me come back has her thinking otherwise and that there might be some hope.
More script. Interpretation- "I want you to stay on as Plan B until I see how Plan A goes."
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Last Tuesday we’re talking and she casually tells me she’s signed up for dating sites and asks if I would want to know if she went on a date with someone. That she doesn’t want to know if I go on a date unless she asks. I’m floored. Gutted. I lose my cool and she reminds me we said that even though the separation wasn’t about seeing other people we (she) did say we wouldn’t be exclusive because she didn’t want to feel tied down.
I get why you're gutted. You are hanging onto some threads of hope and misinterpreting her signals as meaning she may have changed her mind, and now you know she hasn't.
So where do you go from here?
Detach. Let her go. Accept that NO MATTER WHAT bread crumbs she may throw you, the marriage is OVER for now. That's not to say there's no chance of recon, but that is way down the road. And to get there, first you have to let her go and pursue your own, independent life. Remake yourself into "the spouse only a fool would leave". Stand for your M, but don't pursue your M. Give her time and space.
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But I also start to realize how dependent I am on her for my happiness. I wait for her texts. I wonder what she’s doing when she’s at the studio. I look at Facebook to see what she’s posting. It’s constant. And brutal. Which makes me realize that I have to detach if I’m going to survive this, which is how I ended up on this site.
Yes that is perfectly normal, and yes you do have to detach for your own sanity. It's not as simple as flipping a switch (oh if only it were!!!) It happens slowly over time. You detach in phases. Be patient! Just understand things are not going to magically "go back to normal", that ship has sailed. All the snooping will only make you miserable, so start by trying to shut all that down. Don't "unfriend" her on FB, but "mute" her profile so you don't see her posts when you log in. Quit checking her profile. Don't snoop in her phone or anything like that, take it from me, you're more likely to be confused by what you see then to learn anything useful. It'll just leave you spinning even worse.
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At this point my goal is to detach and continue to GAL. I also need to figure out if I really want to fight for this marriage or if I’m just fighting for it to avoid the inevitable pain.
We all resist change! I was married 20 years so I get it! You just want life to "go back to normal". It won't though, you've got to establish your "new normal". It's a grueling process but you can do it!
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Problem is, I can’t determine which emotion I’m feeling at any given moment is “real” and which is anger, hope, resentment, or love.
Read, read and read some more! It sounds like you've read DB/ DR and possibly The 5 Love Languages as well. Also check out The Happiness Trap (it will help you understand your feelings are ALL legitimate, own them!), the Married Man Sex Life Primer (great book on alpha vs. beta behavior) and No More Mister Nice Guy.