This is insane. I assume the $120k a month is from the divorce? If you are living alone, with your kids grown up and out of the house, it seems absolute bullshit that you won 120k a month. Why do you need that much? That is fucked up. I feel bad for your ex, having to pay you 1.5 million a year for pretty much no reason.
It's to support "the lifestyle to which she is accustomed," no doubt. Also, a lot of judges probably build into their calculation the fact that the woman hasn't been working all those years of marriage, so they're accounting for lost wages and wage growth opportunities, etc.
Try to think about it from the opposite perspective. Let's say you married some hotshot career woman, and you decided to be the house husband. Let's say you were married for 20-odd years, at which point you got divorced. What would you feel you'd be entitled to?
I'm not saying I agree with all divorce court decisions, or with the way they tend to be heavily in favor of the woman in most cases. But a lot of men don't even try to consider the woman's perspective. It's worth doing: if not for sympathy, then at the very least, to understand why you need to try to make a marriage work.