Went to Netherportal from overworld, a few things happened:

1) Nether Chunk was different; cobblestone base was gone
2) Portal/obsidian did not render in Nether
3) I plunged to my death

So I respawned, got more obsidian, built another portal lower down so I didn't plunge to my death. I then couldn't find my lost items, went to re-enter my Nether portal back to overworked and immediately died/suffocated in Overworld.

I don't know where I ended up in the overworld but it looked like my second portal didn't save when I changed dimensions, so it tried to re-render another portal somewhere else.

Error log showed nothing unique to the nether besides some warnings about trying to render chickens and villagers. Error log is attached.

Is it my computer or is it the game?