Hi Sera,
Welcome to Apple Support Communities!
If I understand correctly, album artwork is showing up as expected in iTunes but the artwork is mismatched with albums on your iPod. One of the easiest troubleshooting steps that you can try here is simply restarting your iPod as shown in one of the articles below.
These instructions will walk you through the process of restarting an iPod touch:
Restart your iPhone, iPad, or iPod touch - Apple Support
This article will walk you through the process of restarting an iPod nano, iPod shuffle or an iPod with a click wheel:
Learn how to reset your iPod - Apple Support
If the issue persists after restarting your iPod, you can rule out issues with content on the device by using the article below as a guide to disable music syncing and then re-enabling music syncing after you've verified the music and artwork was removed from the device.
Sync your iPhone, iPad, or iPod touch with iTunes using USB - Apple Support
Cheers.