Minecraft single player worlds & realm not saving

I disconnected from a friends realm on our home island, joined the realm a couple hours later and got dropped into the nether. Since then (it’s now been around 2 weeks or so) I am still stuck in the nether and any progress we try to make doesn’t save. I go back to spawning with 6 torches, an iron pickaxe, water bucket, a boat and 13 nether rack on my hot-bar. This ‘bug’ came about before the most recent beta came out but has gotten worse since. My friend has been in contact as we’ve lost a lot of progress because of this, including a full double chest of mining loot, and several enchanted pickaxes.