I'm not too good at reading Java error logs, but it looks like maybe your Z coordinate is somehow screwed up. Since your friend can respawn normally, it seems that the problem comes from something specifically related to your player's saved data.
If that's the case, you can try resetting your spawn point coords from console with the command:
/spawnpoint <player> <x> <y> <z>.
You can also try deleting your player data file, it's in your server folder /world/playerdata/ and is named with your UUID. You can also try going through any plugin data that stores player information (such as your Essentials player data file in /plugins/Essentials/userdata/ ) and reset them too by simply deleting them. Before deleting player files though, be sure to make copies as backup so that you can retrieve your items, xp, sethomes, permissions, etc. later on.
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