It makes sense.
When it was just for fun, it just seems like indulging in a fetish, you wanted an open relationship and maybe he didn't mind that other people got off to you, and maybe he did have a bit of a cuckold streak which made him cool with what you were doing before.
But now that you're doing it for money, it's gone beyond that. Now you're just a pornstar/prostitute/whore. Now it's not so fun, now you're monetizing and capitalizing on the relatinoship's failures. Now his own insecurities and failures in the bedroom are now made much more real, when his wife is being a slut online ******** other guys for money it makes him look incredibly weak and impotent, and worthless, and the nature of this being online, makes it a possibility that someone will recognize you, or your ******** and make everyone's life a living hell.
You were allowed an impressive amount of liberty in your sex life and his only condition apparently was that you not try to monetize your extramarital fun; However when given an inch you took a mile and by doing that have immensely disrespected him. Wasn't enough that you cuckolded him, but you made your own personal gain more important than his thoughts and feelings. This goes way against the love and respect you claim to have for this guy. Cuckold relationships aren't healthy or respectful situations to begin with, they prey on men who have weakened or no self esteem by selfish, self indulgent wives. The whole humiliation aspect of it is part of the kink.
If you don't want your marriage to fail then you need to have a heart to with him about the whole thing and be honest about what you did, say it straight out without the sugar coating. He sure as hell won't be happy with you, but that's what you reap for disrespecting his wishes. Both of your aims, motives, and desires need to be openly discussed and boundaries need to be drawn (or redrawn), and you both *must abide by them*. Sometimes they may not make a whole lot of logical sense, but the nature of relationships are emotional, not logical. --And perspective must be taken that it's better than nothing at all.
If that doesn't work and you're incapable or unwilling to reel yourself back into control for him, then drawing up the papers will be an eventuality. If you can't be trusted to be upfront and honest, then what's the point?