landing page disappeared

I have created a main landing page with the page builder and a number of ‘sub’ landing pages.
this morning I wake up and the main (most time consuming to built) page has disappeared completely.
Is there a way to retrieve it?
I do not see a trash link in wp posts or pages, so I cannot click on it.
Please help me!
(ps amateur builder here, so no technical knowledge…)

The page I need help with: [log in to see the link]