It says I have used all my storage, but cant find anything else to delete - how to I find if there was attachments connected to Accounts or Contacts as have 1000's?

It says I have used all my storage, but cant find anything else to delete - how to I find if there was attachments connected to Accounts or Contacts as have 1000's?

It says I have used all my storage.
I have emailed for assistance with NO response in over a week.
Stopping me using the upload to email templates which are URGENT as wont let me upload more.
Deleted all emails in zoho mail add on we purchased.
There is only 5mb in email templates and cat search contacts or accounts to see if anything is attached.
Pretty shitty system when it comes to storage - almost as though you want to make it impossible to find attachments and have to upgrade storage.