My mouse isn't connecting

When I joined a world a few days ago, and I got a message saying something like: "Can we lock your mouse? Choose 'Never' 'Sometimes' or 'Always'?" and me, not knowing what "locking my mouse" ment, I chose "never". But then, I relised that my mouse would no longer connect to the game! On top of that, my keyboard wouldn't either! I can only join a game. And that's it. I can't talk in chat, move around, open my inventory, or anything! I really really love this game and want to keep playing it, but I can't seem to get that notifacation to show again or reverse it. And I was wondering if you guys could somehow undo it? Or show me how to undo it? Just something like that. Thanks!