Hi Cathryn, I hope I can help you with this question.
I'm sorry you couldn't back up all your data.
Unfortunately, I don't have that good information to get the data back either.
Several factors play a role in whether the data is still there.
If your user account still exists and it still has a running office license, your emails and data could still be there.
If your account has already been deleted, Microsoft's Soft Delete Lifecycle will apply.
(https://learn.microsoft.com/en-us/compliance/assurance/assurance-exchange-online-data-deletion)
If the school does not have a backup of the email folders or documents, the data is probably no longer available.
Can you still contact the school?
If the reply was helpful, please don’t forget to upvote or accept it as an answer, thank you.