Mojang Claims i don't own Minecraft anymore. And are trying to get me to buy it again! My account is verified and everything. Any solution?

Where's the source? Are you installing from the internet or from windows store. There's different methods to fix this. What's your software?

Minecraft is being shut down next week

Contact their support and find out what's going on.

Hopefully you kept the email receipt when you bought Minecraft. You can use that as evidence you bought the game.