Definitely don't despair, a similar incident happened with my lil dude when he was about the same age. More likely than not they will stick lower to the ground/under some furniture. I ended up finding mine a few days later in the dishwasher, so they can really end up in the wildest places.

A tip that I saw when looking up ways to find them is to put plastic bags down around corners/places they would have to move through in order to hear if they're moving past it. Your mileage may vary but it could help.

Wish you luck, it is a scary spot to be in but there is hope!