As promised here is the info I found for how to clear cache for your PS4 System.
1. Turn off your PS4. It must be completely off to clear its cache. If it's left in rest mode, the process won't work.
2. While the PS4 is shutting down, its indicator light will blink. Wait until it stops blinking — that's when the PS4 is off.
3. Disconnect the PS4's power cord from the back of the console. Don't simply unplug the cord from the wall — it needs to be disconnected from the PS4 itself to clear the cache. Also note that the cord on different PS4 models, such as the Pro or the Slim, may be in a different spot. Check to see if that's the case.
4. Wait at least 30 seconds, then plug the cord back into the PS4.
Your PS4's cache should now be clear, and you can test its performance by starting the system back up.
For Game cache via storage:
Follow these steps to access the System Storage and delete game data:
Open the Settings menu at the top of the dashboard.
Select Storage, then select System Storage.
Select Saved Data.
Choose a game to access the game’s saved data.
Press the Options button and select Delete.
Choose the saved data files to delete, then select Delete.
Hope this helps you out with at least the game crashes you've been experiencing! Also I'd suggest playing the Sims 4 in Offline mode for now. (When in game, via start button >>>options. Or simply known as The Sims 4's Settings panel and by selecting ”Other”. From there, just untick the ”Online Access” option and you'll play the game Offline.
