Hm that is not supposed to happen.
Just fyi, you lost your realm as well? Realms and characters have different save files, and your realm should still exist with those 50 chests full of loot.
For the characters to be reinstated, you actually need to use the tool that Moon has released for that here: Patch Notes | Together Hotfix 9
Could you please start there first?
Let me know if any hiccups arise!
Silas