And you won’t, because no one can accurately forecast future performance (and investment managers are disallowed from making promises about future returns).
At some point after the stock markets bottom out, it will eventually start climbing up again but unfortunately no one can say when that will happen or at what pace the markets will recover.
I am not an investment advisor and I have no basis to provide investment advice as I don’t know your whole financial picture, so please take this only as general advice. If you’re able to continue contributing to the 529, you may want to do so as you’ll get a tax benefit when you withdraw for qualified educational expenses. This will especially help if you’re in a higher tax bracket.
You may also want to check how your portfolio is allocated. NJ Best provides multiple options such as “conservative”, “moderately conservative”, “aggressive”, etc.
With a 2-3 year horizon, you would want it to be conservative (or close to it) to preserve assets.
Hope that helps.