Spawn chunk completely glitched/spliced

Logged in, went to go out the front door and it was blocked by sand. Looked right and have a ravine cutting through the base. The back door has been replaced with a mountain, and when I did get outside I could see lots of chunks of desert and woodland randomly placed, and bits of them have some details from my base in them (it straddles a desert/woods border). My donkey looks like hes had a sand mountain land on him (rip), zombie villager bob has been set free, and I have 10-15 iron golems where I had 3 last night. A fire I placed and broke under a bee hive that's in my inventory has duplicated under the hive again.

I had several crashes on 19w38a yesterday when breaking blocks, shut down everything, came back onto 19w38b and everything was working great (donkey still disappeared though on dismount), headed back to the base, walked the front door and did some inventory and logged out - all normal, no crash. I did have a random hill appear two weeks ago in the desert but it didn't look like it affected anything and I couldn't see where it had come from in the surrounding area so I left that as is without reporting - That also appeared after a normal log out session, not a crash - 19w38a is the only version I've had crashes on. I'm a new player so I assumed that was just a normal thing.

Hope there's a fix? I also took a fair amount of screenshots but can't upload them, I'm getting 'Jira could not attach the file as there was a missing token. Please try attaching the file again.'. I'm using the same file path as I did yesterday, sorry if I'm being a massive fail here.