I know you’re kicking yourself, but try to forgive yourself. You’re under pressure now, but someday you will be glad you did well in college no matter where you go.
–That’s as long as you researched and visited schools first, and applied only to schools where you’d be happy to attend–even the “safeties.”
Mistakes happen to everyone at some point.
It’s possible admissions won’t notice, they’re reading a lot.
You know that the essay is the least important aspect of the application. It makes a difference primarily when choosing between similar applications. But it can’t compensate (usually) for being out of the general ballpark.
Just be sure to correct the mistake before sending it out with other applications.
You can make corrections on the CommonApp, but not on the version that already went out, as you seem to know already.
Go for a run or do something that makes you feel good about yourself.