She's Letting me go

Well OP didn't actually PM me, and there seems to be some desire to hear what I'd advise, so I'll just outline some broad strokes on what I'd say to him.

The following advice is very much NOT canonical Red Pill. In fact, some of this advice is so dangerously FUSCIA that if you squint hard, it may actually seem downright BLUE. I'm approaching this as if I was advising a friend in real life that had no idea what the fuck Reddit was, let alone the Red Pill, who came to me and said, "Jack, man, I think I fucked this up, can I fix this?"

Take a deep breath. You have kids. The way this works is you'll spend some time apart, then you'll see each other again. You're talking like you just had your last conversation with her. She doesn't like you very much now, but she can't be hell-bent on nuking your marriage and plunging back into the world as a single woman pushing 40 with two kids. Divorce, even in the least disruptive iterations, is always a huge fucking pain in the ass.

"I stupidly expected her to react too quickly to my improvements and then pushed the dread too far."

That means you probably weren't acting like a dipshit for all that long. Imagine your relationship is a soda machine. A sudden and immediate negative jolt -- e.g. you making some bad financial decisions that caused your family to lose, say, $25,000 -- is jarring, but it's unlikely to knock down the soda machine. Or it may be so jarring that the soda machine actually bounces off the ground and can be easily stood upright again. I've been divorced and have a handful of friends that have gone through divorce, and it never happens as a result of something short-term and dramatic. Sure, the wife takes off and stays with her family for a week or something, but reconciliation usually happens. No, divorce happens when there's a slow a steady pressure tipping over the soda machine. That pressure is fueled by you stalling in your professional goals, letting your social connections evaporate, becoming unmotivated to maintain your fitness, and surrendering the agency and burdens of decision-making to your wife. That is what causes you to have a 0% chance at reconciliation when your wife says, "I want a divorce."

With that said, go see some sort of therapist. You clearly have some sort of deep-seated insecurity or inferiority complex that Red Pill content opened up. I understand, at an academic level, why a sexually frustrated single dude in his early 20s, would read the main TRP sub content saying WOW LOOK AT WHAT SHITTY ENTITLED WHORES WOMEN ARE. But, a married guy with two kids in a seemingly functional relationship, you clearly got way too "triggered" by this (to use my favorite SJW parlance). This is why you regret ever reading any Red Pill content. You regret being triggered.

What you should regret was not deal with the psychological baggage in your mind that fueled the aforementioned insecurity/inferiority, at some point. A lot of people can do this on your own, but clearly you can't, or else you would have done it by the time you reached your mid-30s. So you will probably not be able to have a healthy sexual relationship, with your wife or anyone else in the future, if it comes to that, until you unpack that baggage and sort it away for good.

She told me tonight she's realized that she can't make me happy and is letting me go.

I lost her trust, and It looks like there may be no coming back from that.

Translation: "I doubt think you'll ever be able to get over these psychological hangups, and so any time we have a conflict, I hate that I'll have to wonder if it's really about you secretly resenting me because you didn't get laid enough in your college/post-college years before we met, and some random people on the internet told you that's because all women are actually shitty whores.

So, your reconciliation is pretty much based on removing that doubt. This is why you can't just say, "look, that Red Pill shit is stupid, let's just have a do-over." Because it's not really about the Red Pill anymore. It's her now realizing, damn, he may always regret he didn't have have more sex before we met. And even if you say, "no really, whatever, I was just buying into a false ideal promoted by toxic masculinity," but she's not going to believe you because, well, you just went off the deep-end, behavior-wise, because of some shit you read on the internet. Actions, not words. Remember?

So, you remove that doubt with more actions. Which means you can't say, "my asinine behavior was triggered by some deep-seated insecurities that I've dealt with now that I'm seeing a therapist, problem fixed, right?" In the short-term, give her some space, focus on your kids. Don't brood at home if the kids are with her, go see friends and keep yourself distracted. You will probably literally say to them, "I just feel like I'm keeping myself distracted so I forget how miserable I am." Yeah, no shit. That's the fucking point.

Because you do need to reach some sort of acceptance that this could be over. At some point, perhaps in as little as week but potentially several months, you will have some sort of conversation with her. And she will probe how you feel about things, and you'll Own Your Shit and say, "What do you mean? I fucked things up, end of story. Sort of surprised you'd think I'd think otherwise." And given the passage of time and space, she'll be more likely to take any words at face-value, so she'll probe some more, essentially to see if you truly "just get it" or if you're just telling her what she wants to hear.

So that's the conversation where you also say something like, "I saw a professional for awhile when you took off, helped me sort through this shit." This level of self-reflection will almost definitely cause her to probe even more. You don't need to puke out your entire therapy catharsis, just discuss it at a high level. Clearly you had some baggage. You cleaned it out.

A reconciliation will not be an overt discussion. It will not be some deliberate conversation where you tell her, "I want to give us another chance." It will not be you writing some dramatic letter, deconstructing all your mistakes and throwing yourself upon the altar of her forgiveness. More likely, it will happen as an event, in a setting that inspires the familiar, warm feelings you both had in your marriage. You will host a game night at your place with some mutual friends. You will mention this to her and invite her. She'll come, and you'll be on the same team as you play Taboo or some shit, and she'll shriek, how is it possible that you guessed the word before I've even said anything! Your friends will leave, she'll help you clean up, you'll ask if she wants another glass of wine, then she'll ask you if you want another glass of wine, and so on until it leads to you both stumbling drunkenly into bed and ripping your clothes off.

And she will ask you, in the morning as you both sheepishly roll out of bed in a half-hungover haze, "so... did last night mean anything?"

And you will say: "It means I want you to move back in."

This may seem like a tutorial on "How to Plug Back In," or less charitably, "How to Trick Your Wife You Plugged Back in."
But it's not really possible to do that even if you wanted to. Love in a marriage is never truly unconditional in the literal sense of the word. Qualities that make you virtuous do not necessarily make you sexually attractive. Expanding your hobbies and social life outside your marriage is a constructive thing to do.

You got some constructive advice here. Take it to heart and move on. At some point your wife will say, "oh, I rebalanced our 401K plan and moved a higher allocation to bonds." And you will pause. The pre-Red Pill you would have said, "oh, OK." But now you're not sure. This seems like a "Captainy" thing to do, a decision like that, and so what does this mean? Does your wife not respect your financial acumen? Is this because you've typically deferred all financial management to her? Are you making some sort of grave mistake by doing that? Are you just digging yet another grave for you marriage, as your ignorance about Vanguard index funds drives her ever closer into the arms of Chaddison Thundercalves, C.P.A.?

And that moment will hopefully remind you that of all the things you learned in your brief foray in the Red Pill, that the only good marriage is one that has both partners mutually adding value to each others' lives, and not at the expense of adding value to their own lives.

And final step in your catharsis, is when it strikes you that your definition of "value" can be whatever the fuck you want it to be.