Reloading a minecraft world causes automatic death

I recently had started a new survival world. I just came out of the cave and was on the surface and exited the world. After reentering I was stuck suffocating in a wall as soon as I loaded in, with my health at 4 hearts upon entering, eventually killing me before I could even comprehend what had happened. Keep in mind, I was on the surface, had moved around from where I had poked back out, in peaceful mode and my health was full before I exited the game beforehand. The same thing had happened before, but I was in a boat in the water before exiting the world and I joined back to being at half health, no air bubbles and taking damage. I had narrowly avoided dead there.