If you fear that your lack of success may cause a rift, discuss this with thoroughly your wife. You say you sense that there is resentment, but you don't know that for sure. Work out first if your fear is substantiated and then if and only if it is, find a suitable compromise. For all you know, it could simply be an unsubstantiated fear.

Moreover, you can try negative visualisation. Imagine what it'd be like if your standards of living took a hit, figure out how you'd deal with a lower standard of living, then realise it's not so bad after all. To Stoics, our material conditions are mere indifferents and whether we are wealthy or not doesn't impact our ability to live a good life.

"If my wealth goes away, it takes with it nothing but itself." Seneca