Game is suddenly really laggy and slow

I have a Macbook Pro M1, running Big Sur 11.4. Plenty of memory and RAM to run the game.

In the last week the game has got really laggy to the point it's unplayable. Loading screens take forever switching between a household and manage worlds. Actions are really slow, outfits take a few seconds before changing. I have to click on things several times for it to acknowledge it. Conversations are virtually impossible, because it takes so long to register the action.

I've also found that a can't 'right click' (ie clicking with two fingers on the trackpad) which means I can't access CAS by clicking on the Sim.

I've tried deleting CC and it still has the problem. I don't know if it's a coincidence but it's been like this since I bought the Industrial Loft kit. I'll try removing that and see if it helps.

Has anyone else had this problem recently, and do you know how to fix it?