WP Vivid not working…and screwed access to my WP backend

Hi,
I already submitted a ticket, but I need a solution as soon as possible, so I post here too. Just in case…
I just tried WP Vivid for the first time. It just screwed something on a site I’m working on.
It couldn’t make a backup and I activated “optimized mode” and tried again.
The backup routine was stuck again and wouldn’t let me cancel. It just went on and on…doing nothing.
So I logged out and couldn’t log in anymore. Already tried to change password…didn’t help.

I must say, that I’m disappointed. I expected a more refined product when I recently bought the lifetime license.
I never had another backup plugin refusing to do a backup on that host and certainly not fucking up the site.
Sorry for the language, but currently I’m mad…
Thank god the front end ist still running but I should have made updates and now I can’t.
What can I do to fix this?
Thanks