How do I fix a Sims 2 corrupted game?

I've had The Sims 2 for a while now, and just lately it seems to have corrupted the entire game, not just one neighbourhood. I can't send my sims to college and multiple items simply do not show up, I've lost showers, tables, doors, exercise machines and more. I was wondering if there was any way to fix this, I know it's an old game but I love playing it a lot and would really appreciate any help I can get. (It's not CC, I got rid of all my CC and it still had the same problems)