You will need to keep in contact with Wix Support as it is not a code related issue on your site for which this Corvid Forum deals with.
https://support.wix.com/en/article/live-site-error-error-500-internal-server-error
https://www.wix.com/corvid/forum/community-discussion/error-when-saving-data-to-collection-wde0053
https://www.wix.com/corvid/forum/community-discussion/important-error-wde0053-internal-wixdata-error
https://www.wix.com/corvid/forum/community-discussion/urgent-failed-to-load-initial-data-error-wde0053