I managed to save myself a decent nest egg - but they're going to crash the market and it will be fucking worthless.

Depending on the exact setup, it does not have to be. Assuming it's in stocks or a stock fund, you can always hedge it against downturns with options. Of course I do absolutely recommend really understanding that first before using it, as you can also gamble and lose money faster. But when you do, contracts exist that allow you to 'configure' a portfolio that, temporarily, will cancel out any market drops. Barring ethical reservations, of course. Naturally, that also carrries the risk that the bank selling the contract goes tits up, but it seems you're already in that boat. To manage that, you can aim for diversification across multiple banks and instruments. Not an advertisement or anything, but since covid I've found directly owned old-school crypto to be a good hedge in rough times (but need to get in low and work in the 2-5year timeframe). But for the love of god, leave out all emotions, calculate with a spreadsheet and don't put all eggs in one basket.

I'm not any kind of advisor, just got pissed about the shit economic situations we lived through and looked into what can be done about it.