Nether coors messed up?

I was in my world and i wanted to head to a farm far away, so i used the netehr, because its faster, but while being teleported to dimensions, my game crashed, so i closed an reopened minecraft, excepcting me to be back at base, but no, i was in the nether, suffocating in netehrrack, i looked at my coords and noticed i was where my portal is in the overworld, but in the nether, i managed to get back home buy if i made it any higher than 256 i wouldve lost the world forever, because im not suer if the new height limit is added in the nether, i think the game mightve tried to save while crossing dimesions, because the game crashes fora while when its saving, its annoying, i almost died from it, lucky i ate the god apple, because i didnt set my spawn, also if anyone knows why the game freezes while autosaving and knows how to stop iy that would be great thanks!