OP, here is my 2¢:
1. Your marriage sounds like you both have checked out. You married at that age a lot of people do when it is the next step, there is peer pressure, clocks are ticking, etc. Many people go down that road and get divorced and if no kids are involved then no harm no foul. You both are young enough to meet someone else and remarry if that is what you want.
2. You taking action and hooking up with Cartoon Bewbs was you acknowledging it is over on your end. If you cared about your wife/marriage you would not have crossed that line. Was it wrong? Sure. But for all you know your wife is already having an emotional or physical affair of her own. As you describe it there isn't much physical or emotional chemistry between you and your wife may be getting those needs filled elsewhere.
3. Do not tell your wife you cheated, there is nothing to gain.
4. Have an honest talk with her about the marriage and both of your concerns (minus the affair). Divorce may already be on her mind and she is afraid/ashamed to bring it up. After talking you two may realize it is worth staying together. If she is on the same page as you in regards to divorce, then speak to an attorney next week. With no kids and no fault depending on which state you are in this thing could be final in 90 days.
5. Cut contact with Cartoon Bewbs until you are legally separated and living on your own. If she legitimately wants to be with you she will comply. You run the risk of her finding another sex buddy in the meantime, but better to find out now than after you move to her city.
6. Realize that if you pursue Cartoon Bewbs after you are separated that you are playing with fire. She may be subconsciously using you as an emotional and sexual bridge from bad marriage to singledom. You go all in and wake up six months later alone, she is done with her rebound fling and looking for someone better.
7. These types of situations rarely work out. I have a friend who went down the same path a few years ago and it crashed and burned. He said if he could do it all over again he would have steered clear of the hot separated mom who hadn't been ####ed properly in years. The crazy sex can be blinding, as it always is.
8. Your situation may be the exception. I think the history and chemistry that you two have is a positive. This isn't some broad you just met at the neighborhood BBQ. Also, she has money so you are not just a fill-in provider.
Tldr: talk to your wife, leave out the affair, file for divorce, cut contact with (30)(F)/beat off furiously until separated, go live the life you imagine. And pics.