I'd leave, because it does sound toxic and abusive (the verbal abuse still is that regardless of the cause (eg "illness made me do it")). You can't be yourself around him, which is toxic as all hell TBH, nobody can live healthily in a constant state of self censorship and walking on eggshells.
He doesn't actually love you, he loves the person he wishes you were. The one who isn't sarcastic, the one who never questions him, you know...the one who doesn't exist. You don't love him either. You love feeling looked after and protected (financially anyway, you're certainly not being protected from his temper!).
You could stay and play nice for now but it won't last. You sound a few months away from getting the ick, a few months more from getting resentful that you're having sex with someone you don't really fancy or even like much, because he has a nasty temper and he's heading into old man territory when you'll have barely even turned 35. Marrying him will make you feel so trapped, because you are (whilst you stay with him) and marriage will cement that.
So you've a choice to make. Who do you want to be?
One step up from a prostitute (that's how I consider gold diggers, which is what you're talking about being), doing whatever it takes to keep the cash flowing in, financially cushioned from life's realties by someone older who embarrasses you by existing and in this case has a less desirable personality.
Or are you going to be someone who lives life on your own terms, experiences the freedom to be yourself and be completely responsible for yourself.
I'm not particularly motivated by money (and I'm not well off, so it isn't that) so it's a no-brainer for me. I'll always choose happiness and freedom, whatever form that takes.