Sighting of Boogeyman

I was playing my minecraft on nintendo switch and played with seed codes, after putting in some weird seed numbers i decided to put in a seed saying,"weirdworld335".So once I spawned in after 27 seconds I realized that this world was not normal, there were giant holes (about 11x11 blocks long) that leaded strait to the void, after traveling 10,000 blocks from the spawn there was a glitch biome that covered the rest of the world, after about 3 minutes of traveling the overworld music got reversed and all the animals died, that's when I knew thing weren't going to go great, trees started growing on obsidian blocks, monsters like zombies and skeletons would not burn under the sun, instead under the moon and soon i found a sign saying:"don't look up", but i did, and it was a mistake, right above me was another player (even though I was in single player) with a skin that was all black but his eyes were wight (like herobrine) and in the chat he said,"what are you doing" I replied saying "I just wanted to see what was above" and then this mysterious entity said back "GAME OVER" and my game crashed.I hope this is resolved as how it might be a trick or something by a hacker, but I hope this problem is resolved.Thank you.