Thought I'd give a little update aswell. I deleted the weird oxyn- something folders inside the mutables and it gave me back the space without any harm done to my PC. Restarted too and everything still works.
Also worth noting, it seems like the folders show that they're empty until you actually open them, they certainly are full of your gigs though.
Honestly I dont think I'll try a reinstall until they patched things up a bit or optimally release a steam version cause my god this was such a headache for a pc illiterate person like me.