Worst downgrade ever?

Without any request for user consent, Microsoft has downgraded Outlook today in a way that has wholly wrecked my ability to use the programme.  No visibility of emails other than immediate past, no functioning way to change this (changing settings for the unrequested, useless "focused inbox" does not work); no toggle switch (as Microsoft claims there is) to revert to classic Outlook; and, of course, no access to user support.  So, is there any guidance available on this site on how to make Outlook usable again, or do I simply have to find another email programme?