I added too much pepper to my soup. What can I do?

try adding some creme fraiche to the soup to lighten the spice? if a huge amount fell in, it might not be salvageable!

You just might be able to salvage most of the soup by refrigerating the pot and having the pepper settle to the bottom of the pot. Then you could ladle out as much of the soup as you can without dislodging the pepper on the bottom. Some of the pepper will obviously have flavored the soup already, but you might be OK. Had a Bloody Mary once with a quarter inch of pepper at the bottom. As long as I drank from the top half of the glass it was fine.

Pepper is such an assertive spice....other than diluting the entire soup, nothing really neutralizes pepper.

It sounds like a huge amount of pepper...maybe not savable.
If you want to have a go and these go with the flavor of your soup, try adding carbs (bread, potato or pasta) and/or dairy...both of these absorb and balance a large amount of pepper.