I'd save the water changes for tomorrow if it just happened. Wake up early and give it a go.
To reduce the need for changes now, try sucking water out into a bucket feeding into some filter material. Let the material catch the stars, then dump the water back in.
I'd then toss in extra carbon and maybe a bit of amquel or equivalent. Probably not a full dose. I'd also consider adding a bubbler, though I can't say why, and I think higher pH makes ammonia worse. However I thought ammonia neutralizer reduces oxygen.
I believe the ammonia neutralizer should get you through any possible major issues, and jump on water changes to keep things stable.
If you're running a skimmer be careful it doesn't start overwhelming your tank.
Also, remember sand has very high surface area and holds a lot of bacteria. Probably comparable to the rock in a tank, especially with man-made rock. I would put the sand back in if possible, since you want that bacteria in there.
Best wishes! Stressful!