Duplicated Gmail accounts and all email

After up date to macOS Big Sur on my MacBook Air early 2015 both my email accounts duplicated all emails. They are in sync as deleting in one the duplicate also deletes. I have 5 years of email saved in mailbox . Trash and junk were also duplicated. The look of my gmail changed and I no longer have a profile photo or a settings. This duplication is causing me to have to scroll all over when saving an email. How can I get this back to a classic look or even a look with settings icon?