We can see a lot of js errors that are independent of our theme via the browser console.
Try to disable 3rd party plugins by re-naming via FTP and check how it works then.
Did you make changes in files of the child theme? Check additional customization there.
Try to remember what you did before it broke.
Check server error log, are there any errors?
Let us know results, provide temporary FTP access, so we can take a closer look.
