None of my Minecraft worlds will load on my main account.

Hello, I'm playing on Xbox Series X and I've been trying to solve a problem that I've been having for the past 2 weeks. Basically, my friends and I were playing on this one world for 2 or 3 months, and since I'm the host, I had to start the world everyday so everyone could play. One day, I try to start the world just like evry other day, after a few seconds on loading and "syncing user data, this may take a few moments", I have a message that tells me "There was a problem loading this world."

So I try to load it again and the message "syncing user data, this may take a few moments" flashes on my screen for half a second, and nothing else happens. I then try to load another world that I was playing solo, the same thing happens, the message flashes for half a second, disappears, and leaves me in the menu where all my worlds are. I then try to make a copy of the world my friends and I used to play, same thing, again. I then try to create a new "test" world, which actually worked, I play on this world for a few minutes, then I leave, try to start the main world again, doesn't work. I then try to load the "test" world, turns out the same thing happened, the message "syncing user data, this may take a few moments" flashes for half a second, disappears. Turns out that this issue affect every single world that I created with my main account.

Then, I start my old Xbox One X, which I used to play the on the world with my friends. Exact same thing happens, "syncing user data, this may take a few moments". Then, I log in my second account, which I've never played Minecraft with. I create a new world on this account, start to play, leave the world and try to come back, it actually works! So my opinion is that the problem come from my account, more than it comes from Minecraft itself. Problem is, I really want to play on my old world with all my friends, and I'm pretty sure I am the only one who has had this problem so far, since I could not find anyone on the YouTube, Twitter or Reddit who had the same problem. If anyone can help me (help us, actually, because my friends also want to play on the old world), please give me any piece of information you have.

:)