Hello @debsmith,
Sorry to hear about this experience. I would request you try resetting Illustrator's preferences by following the steps shared in this article (https://helpx.adobe.com/illustrator/kb/troubleshoot-preference-issues.html) and sharing your observations.
Disclaimer: Please note that resetting preferences will remove all custom settings, and Illustrator will launch with the defaults. You may take a backup of these settings from the location mentioned in the article.
Also, kindly check if the Display Resolution and Scaling settings are set to the defaults, relaunch Illustrator, and check if it helps.
Looking forward to hearing from you.
Thanks,
Anubhav