Sending a check to the IRS is a rite of passage. It is boring, but it is your boring. You are participating in a tradition older than sliced bread. People have mailed checks to Ogden since 1954. You are part of a legacy.
So, lick your envelope. Stick a cat stamp on it. Say a prayer to the postal gods. Mail that check to the right address. You did it. Now go celebrate with a doughnut. You earned it. The IRS can wait for the next round.