I also had a cheating shithead leave me for some asshole coworker 10 years her senior. I probably would've been one of those suckers who got dumped without even knowing of the affair if I hadn't caught her, on Labor Day of 2018. When she revealed her true colors, it was a mindfuck. The cheating didn't bother me nearly as much as of the big reveal that she was stringing me along, had no actual feelings for me whatsoever, and gleefully treated me like an enemy combatant the moment I caught her--when moments before, she was putting on her Oscar-worthy performance of Loving Caring Soul Mate.
Don't believe her bullshit. She's a proven liar. Don't let anything she says from here on out get inside your head. Your sense of self is already damaged. Your identity is in ruins and you're going to have to rediscover yourself over the next couple of years. Your self esteem is shot after having gone through the ultimate rejection, the one where they shitcan you and don't look back, like none of your time together even mattered. You're going to have a void in your free time that you absolutely cannot be filled with ruminations of why you sucked as a husband and what kind of life you're missing out on and all that garbage that you can barely keep from filling your head. The truth is, she wasn't the woman you thought she was and none of those future plans were going to transpire the way you wanted anyway. Thank your lucky stars she revealed her true nature this early so you have even more time to build a newer, better life for yourself.
Don't worry about what she's saying to anyone else because they're going to believe what they believe anyway. Unless it's someone you ABSOLUTELY want to keep in your life, just let her peddle her wares to everyone else and put it out of your mind. Maybe they'll see through her bullshit one day, maybe they won't. Eventually they'll be so far in your rearview mirror that their opinions won't even register. Nurture positive thoughts by assuming she's such an asshat, they'll eventually catch onto her shitty ways anyway and some kind of cosmic karma will descend upon her. Oh and this is important: don't count on karma, because in the real world, shitty people can skirt consequences like pros. Another thing you'll eventually let go of is giving a shit whether or not she pays for this in some way. You're still early enough into this to maybe feel a "love" attachment of some kind, so this is distance future stuff.
I'd highly recommend continuing to play it cool and leave the pettiness out of it. I had one of those cold shits who wanted to sweep me under the rug, silently, before her dinner got cold. If yours is similar, she'll want to just give you all the things she can live with parting with and get you the hell out of there ASAP so she can launch her Shiny New Life with Prince Fuckwad. Bringing petty shit into it will only spur her callous nature to usurp the single-minded path she's on at the moment and attempt to get even dirtier. BUT, if she does get dirty with you, protect yourself to the best of your ability. Stay out of the mud, but keep those defenses manned at all times.
Once you're through the legal stuff, then it's just the devastating emotional turmoil at your feet, and really that's something you've pretty much got to passively wait out anyway. During that period, I highly suggest investing your time wisely and distracting yourself with a variety of self-improvement actions. Work out. Learn how to do something you've wanted to do. Travel to a few places but in a real way where you soak up the environment and not some superficial way that won't leave a lasting impression on you. Try to be a better person to the ones in your life who truly matter, the ones who actually support you. You'll mindlessly go about this stuff because you'll be so wrapped up in the pain of this process. By the time your brain stops dumping shitty thoughts back into itself, you'll wake up and realize that you've accomplished 6 to 12 months of self work and you can go set and forget mode with these healthy behaviors and continue reaping the rewards.
Don't get too hung up on what was real, why did she do this, etc. etc. You'll NEVER KNOW. Such is the cross you'll bear, and it won't ever go away, although it will greatly lessen in time. Learn from this experience. Realize that while you might be able to open up to another person again some day, you've got to look out for yourself first and foremost, because nobody is going to do that for you. Get swole as hell from bearing that cross. Springboard from this shitty traumatic experience into something legitimately better for yourself. You're in a weird primordial ooze phase where everything's in pieces. We rarely find ourselves in this situation, so use it as an opportunity to rebuild in a smarter, healthier way than before. In a year, two years, you'll eventually recognize that this quitting assclown did you a favor by disappearing and not wasting any of your time. A clean break is much harder in the short term but pays dividends if you don't it derail your life.
Keep coming back, we're here to help you through this.