Things will likely rebound eventually. On the micro scale, if you understand psychology, you’ll understand that some people will always buy on dips, and any path down (or up) isn’t a straight slope.
So, if the markets fall 3-4% in a week, a leg up of 1-2% is expected, at least for the short term. Macroscopically, even if you get a 20-30% dip, it will eventually rebound. Maybe in a year, maybe in five, maybe in ten. If you’re willing to buy and hold quality stocks, you’ll be OK.
Lastly, not all stocks move with the markets — the right stocks can even be undervalued in the mother of all bull markets.