HELP! Xbox Farmhand account corrupt!

My friend hosted a farm on Stardew Valley and we played abput 40 hours worth logging on and off without a problem and we went to log on today and a newer farmhand has access to my character and I don't anymore. He joins the farm AND IS ABLE TO PLAY MY CHARACTER! The same character that should only be accessed by my Xbox account. So now if I try to play on the world there is obviously no room for a new one because there are only 2 cabins and 2 farmhands, PLEASE HELP!

 

I would try reaching out to Xbox support. I'm afraid we're not very familiar with the console MP mechanics, but they shouldn't be able to access your character unless it is a local connection game.