Go to your Google Account. On the left navigation panel, select Security . On the Your devices panel, select Manage all devices. You'll see devices where you're currently signed in to your Google Account or have been in the last few weeks.

If you have a phone number linked in gmail then try changing the password and use the phone number for recovery. In case you have recovery email in gmail then trying changing the password using the recovery email.

To protect your account, we limit the number of times you can attempt password recovery via email, SMS, or Account Recovery form. Google temporarily disables a particular account recovery option after too many incorrect attempts. The recovery option will be re-enabled on the date indicated below that recovery option.

If there's suspicious activity in your Google Account or we detect that your password has been stolen, we may ask you to change your password. By changing your password, you help make sure that only you can use your account.