Website “gone” after deactivating all plugins – blank pages

Hello guys,

I was trying to handle a small problem with my design and in doing so I marked all plugins and deactivated them at once to see, if one if them was the problem. When I hit the button, the site turned white and nothing else happened.
And that was it. Since then, I can not access my blog or wordpress dashboard in any way. When I am in my wordpress.com dashboard, my blog is not there any longer. It just vanished. Any URL leading to my site ends up on a white page.
Does anyone know what this might have caused and if there is a way to undo it? Everything worked so perfectly fine! Plus I am a total beginner and haven’t the foggiest.
I am using the latest wordpress version.

My URL is: https://laurelkoeniger.eu

Would much appreciate any kind of help.

Best regards,
Laurel