Don't try to pull any BDSM on your wife, because she will not respond positively. You aren't qualified for the dominant position, in her mind, since she is making more $$$ than you. My wife tried to read 50 Shades since her friends had raved about it and and she couldn't finish it, because she said every third sentence was some variation of "Christian Grey is the richest man in the world." It's not the idea of bondage sex with Christian Grey that gets women revved up, it's the idea of any kind of sex with "the richest man in the world."
Ever heard of "female hypergamy?" That's what's going on here.
I am a big fan of "Biblical Marriage." And by that, I don't mean "Feminist Churchian Marriage," I mean a marriage like the kind the dudes in the Bible lived. Ever actually read it instead of just letting some harebrained preacher tell you what's in it? None of those biblical heroes of faith, except for the wittol Abraham, would mishandle this situation the way you have.
I've got prostate cancer and had my prostate out years ago, with the usual sexual side effects, so I know all about E.D. If this is service related, you need to pursue treatment, up to and including an implant, on Uncle Sugar's dime. With one of those, you can pound your whole biblical harem all night without a rest.
What kind of physical shape are you in? typical American sack of , uh, lard? Is the number on the waist of your jeans bigger than 32? That's too big.
Let's talk war plans. What are your S-2 telling you? Have you put a VAR in her car? Have you looked for her burner phone? Why are you sharing all your battle plans (books, self improvement) with the enemy? She is your enemy in the same way Iran is an enemy of the US. Khomenei declared war on the US back in '79 and our so-called leaders have studiously ignored that fact ever since. Your wife has declared war on you, so quit acting like Jimmy Carter and behave like Andrew Jackson.
Stop planning on leaving. Instead file for divorce and ask for separate maintenance. That way she'll be paying you, since she is the high earner. If she wants to split, she'll be the one leaving. Get the best physique you've ever had. Get your d!ck fixed.
Your wife has had you slotted as a beta/delta provider for a very long time. Far longer than you think. She's a nurse, so there is a high likelihood of extramarital activity in the past that you failed to detect. The boys are out of school now and you have fulfilled your purpose. That's why she "suddenly" wants out. You were the delta who politely raised her kids and now she wants to get plowed hard by some psychologically damaged, very rich alphas.