Hi Clara,
Sorry to hear about your experience. Would you mind sharing the version of the OS & Illustrator?
I'd request resetting the Adobe Illustrator preferences once and see if it helps you out. Please follow instructions given on this help article and see if it helps.
**Please note that resetting preferences will remove all the custom settings and Illustrator will launch with default settings. You can also take a backup of the folders in case you want to. Location is mentioned in the article.
Let us know how it goes.
Regards,
Ashutosh