Instant death upon reloading a world

I had reloaded and spawned into my world I had created earlier today, and I had forgot to change the screen safe area. So I went back to the main menu and changed it, and once I reloaded my world again, it instantly greeted me with the death screen (nothing was around me that could have killed me) and everything in my inventory had instantly despawned, nowhere to be found in the place that I had died in.