Logged on friends xbox, lost everything in minecraft

I play on minecraft bedrock edition for the nintendo switch. Recently I was at a friends house and we wanted to play minecraft, I logged on as a second player for split screen minecraft on his xbox and when I logged in, all my stuff was gone. We dismissed it but a few days later I logged on my switch to play minecraft only to find all my stuff was gone, a year of playing and grinding lost. I was wondering if you could somehow fix the issue or at least fix/investigate the bug. If it helps my xbox live account is Krono06.