Almost all your work would have been in the MODx MySQL database.
I’m guessing that when you moved your site, you didn’t change the name of the database in config.inc.php. That means that both sites would have been using the same database and tables in the DB. If you deleted the one site just by deleting files, your data in the DB would have been fine, but if you did a Simple Scripts uninstall of the site, it probably deleted the site’s database which was also the *other* site’s database.
Your host *should* have had a backup of your DB, but as you now know, you should have one too.
It’s still possible that some of your work is still in the DB. If it wasn’t deleted by the uninstall, it would be there even if you’ve since installed MODx again as long as you used a new name for the DB or did an upgrade install. Someone who knows MODx might be able to save some of it for you. I’d be glad to take a quick look. Send me a personal message here if you’re interested.