Login page redirecting to front end

Hi, my Web site wordminstrel.com/wp-admin is redirecting to the front end wordminstrel.com. The front end is still able to be viewed. I updated all plugs, themes and core WordPress on the 4th April. The Web site is using the Divi theme. It is self hosted on my VPS with a South African Company 1_Grid.com. My VPS is running over 100 other WordPress sites without a problem. I have taken the following steps
1. cleared all the cookies on my browser (tried 4 different browsers all with the same result)
2. Disabled all the plugins
3. Checked and refreshed the htaccess file to ensure it is correct
4. Tried to access the backend through the softaculous facility on the cPanel with no result.
5. Tried to revert to a default theme. I then get the message _ This Web site is experiencing a critical error. When I take it back to Divi, the Web site is again visable on the front end.
6. Spoken to the support enginners for my VPS who are looking into the problem. When I try to upload a backup get the message “Failed to mount the recovery point”
Any ideas here please would be appreciated. Thanks,
Jenny

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