An "Analytic Account" is used to book costs (Bills, Employee Expenses, Timesheets) and/or revenues from Invoices to analyze costs or margins.
It has nothing to do with Google Analytics.
You can read about them at https://www.odoo.com/documentation/15.0/applications/finance/accounting/others/analytic/usage.html
You can check if you have permission to access them by reviewing Access Rights at https://www.odoo.com/documentation/15.0/applications/general/users/access_rights.html and can review all Access Rights for every document type at once via the "Access Rights" Menu in Developer Mode.
An "Analytics Account" is what is needed on the Google Site to support Google Analytics in Odoo.
You may want to verify you can still access the account on the Google side - see https://www.google.com/search?q=lost+access+to+google+analytics+account
If you still have problems after trying the relevant suggestion for you, please contact Odoo at odoo.com/help Support to open a Ticket.