It can be that your host keeps backups for you. If so then I highly recommend contacting support, restoring the 2.9 and upgrading to 3.5 as Ken Says then then to 3.10. If you have the time and energy to do so it may save you lots of problems in the future. I have had lots of Softaculous errors.
Installing and upgrading help
Moodle Version not showing up after upgrade
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