Minecraft Crashes After Trying to Teleport an Extreme Distance
I tried command: /tp ~ ~6000000000000000000000 ~. I teleported, but Minecraft crashed. When I enter my world it crashes. This world is very special for me. How can I fix this? How can I change my position?
There is an external tool called "NBTExplorer" which can be used to modify the data of a save file. You can use it to edit the player location of that save.
Open NBTExplorer and find your_save/playerdata/your_uuid/Pos and edit the values by double-clicking on them. Save the changes and load up your world again.