@KatherineBrown3 ...
Well, that's no good. I've seen other people posting similar screenshots like yours as well. It sounds like you've tried many of the troubleshooting steps I'd normally recommend...such as a different browser and clearing your browser history/cache. Thanks for letting us know you've tried those options already. Have you tried reaching out to your Online & Distance Education department at the University of Nebraska-Lincoln? Maybe they have some ideas for you? Also, have you tried reaching out to Canvas Support? They would be a good resource, too.
How do I contact Canvas Support?
Keep us posted on this issue...so we can know how you were able to get things resolved...thanks!