I have black painted furniture in my bedroom. I had no idea it was

You have to strip the existing paint off first. What is the furniture made of?

The best thing to do is to sand and repaint then seal. You may be able to feather the edges of where it peeled depending on how bad the finish has become otherwise, you may have to sand the whole top. I would then put a primer on the whole top to make sure it sticks and paint it the same color. (keep a piece of the peeled paint so it can be color-matched - all blacks are not the same.) Once you're cleaned it up, put a coat or two of a waterproof sealer on it to protect it in the future. Best of luck with your project.

Any painted surface would be affected by water. Is it a very large area? You probably need to, at the very least do some light sanding before repainting. If you have to repaint just one piece the hardest part would be matching it to the other pieces. Also, remember that shiny paints would show marks, etc.

Is it dry now? Do you have Insurance that would cover? If not, Let it dry out, Rub it down with fine glass paper, Prime - undercoat and then top coat in the correct finish ( Satin or Gloss) It will never be quite the same, but it may help......

I've covered a desk, dining room table, sideboard, and a work station with 12" stick on floor tiles. Turned out really nice. On black furniture a pretty white with black, gray marble pattern would be pretty. Easy remake to scratched and damaged table tops.