Wordpress and website Content Dissappeared

If you overrode all the old files then it’s gone unless you have your own backup. There is a chance the old database is still there, you will be able to recover your sites content (minus themes and plugins) if it has not been deleted. Check in the databases section and see if any of the databases listed there are WordPress ones with your posts in them. For the future, make sure you always have a backup of your files.