I’m not completely sure if you can or cannot recover it. It really depends on how destructive the VestaCP installation was to your existing stack. Assuming everything is there, you would need to treat it like migrating to VestaCP from another server. This would involve using mysqldump to export the database, and then copying files from their original location (likely /var/www/html) to their new location (somewhere under /home/username for the VestaCP user that you use to set up the domain in the panel).
If all of this sounds entirely confusing and unclear, you may need a friend to help out. If you know anyone with experience migrating websites and databases in Linux, I would call on them to review the situation for you. The step by step process here is relative rather than absolute, making it difficult to give any step by step instructions.