Sorry to hear about this experience. Do the steps suggested by @kevin stohlmeyer work for you? If not, I would request you to share a few more details like:
Exact version of OS
Do you get an Error message when trying to launch Illustrator? If yes, please share a screenshot of the same.
We would also request you to share the Crash Report with us so we can better understand why Illustrator is crashing.
While submitting the crash report, please use the same email address, with which you are signed in on this community. This will help us find the crash report and help accordingly.
After submitting the Crash Report, try resetting the preferences for Illustrator and share your observations with us. Disclaimer: 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.