OK. At first thought, there are 2 directions I could imagine you taking, no three.
A. Before that, how do you know you couldn't have a less luxurious but freer life after divorce? And how is it that half of his assets and other divorce settlement elements wouldn't reach you? or that he can keep you poor? or you are afraid of his revenge? Have you actually discussed divorce with a lawyer? Do you have morally indignant family or a very righteous & close-knit church to make you feel ashamed? Are you not really a "kept woman" but a dominated, shamed, abused or terrorized woman whose husband isn't rich at all but IS a fierce captor who has made you feel so low that you can't imagine having the guts to leave him?
When considering divorce, there might be other factors that could make the alternatives to being a disrespected, unloved and betrayed rich woman not as bad as they might seem from the inside of the castle--or poorhouse prison walls. You could consider the options you might have for a supportive community if you escaped.
You wrote so little, as if you were almost out of breath and/or afraid of being caught by spies. If you're taking a big risk to even ask this question, you would be better served by calling a women's support hot line and finding allies nearer and more real than your computer screen.
I could be throwing out foolish and impossible alternatives unless you write more about your situation. But on the off-chance that you won't replay at all, but will see my reply, here are three possible solutions or alleviations I can imagine before knowing anything more:
1. You write as if you were completely helpless, with no escape routes at all, as if your philandering husband has all the power and you have none. So look around for where your power lies, even though you might never have thought of it that way.
B. So why does he keep you around if he wants to be with other women? What do you bring to your marriage that he really wants or needs? These things could be chores (preparing his business shirts just right for him to put on as he leaves for his work) or public appearances that he can't farm out to someone else. Or good biological mothering to the children you have in common. Your own wealth in the marriage might be not tangible at all. So WHY did he marry you, and WHY did you marry him? and how long ago? and what has changed since then?
C. You need to understand what you are or what you do or have that makes you have some power to influence him that you haven't considered. What would he have problems accomplishing or living if you were gone? If you have some gifts to your marriage that he wouldn't want to do without, then you may have bargaining chips for negotiating a more equitable pair bond. That may sound vague, but I'd have to explore your situation financially, emotionally, as a network of family relationships, etc. to see where you'd have leverage to effect a change in the relationship's unspoken rules.
2. The riskiest direction I thought of, again without knowing enough about your situation to test its possibilities, would be "two can play that game." If you don't have economic supports to make ends meet on your own, and you wouldn't get quickly dumped or killed for having your own affairs, then you could select good single men for your own affairs that have the kind of money you believe would soften your landing if you bailed out of your marriage. Such men would also make your husband aware that he can't control you with his money, if other men with money want you too.
I personally wouldn't want to pursue that direction, because it's playing with fire and adding to the numbers of people that would stand to suffer or get violent. It makes for pretty good movies, but in real life I bet it's usually nerve-racking and often short-lived. The culture you live in would also make a huge differences, because you need to understand the rules of amorous engagement and the means of power and protection. I assume women usually understand those rules better than men, because the group or gender with less social power normally understands how to manipulate the more dominant group or gender, while the dominant group uses conventional or "legitimate" power (legitimate because it's normally expected) without thinking much about the consequences.
3. If your husband is generous with his money and doesn't need to keep you locked up because of his own insecurities, then you could pursue "other loves" without them being other lovers. Travel, arts, studies, self-fulfilling volunteer work could give you something more rewarding to love and serve and thus replace any humiliating desperation to wrest back his attention, love and respect from one affair after another. If you could embrace your own passionate lifestyle, like weaving, roadbiking, poetry, scientific research, musicianship, volunteer service (even through churches) in places that need you, whether in America or abroad..
This path would be my favorite, because you're actually using your present financial position to launch your experiments for the next growth stage in your life. And once you're on a trajectory of new growth, that's where your passion and fulfillment will come. So you won't be nearly as concerned about his cruel and disrespectful violations of marriage as you expected it would be. You could end up leaving him in the dust along with his neanderthal vision of male-dictated activities in marriage,
And who knows? You might meet the individual or group that would be far more fitting and supportive for the new you.
If you want more precisely targeted ideas, please answer the questions scattered thru paragraphs A, B & C above.