@bmelendez11
Moving out the whole Sims 3 folder from Documents > Electronic Arts and starting with a new, clean game. If it works you can then add your CC back in bit by bit testing that it all works ok and isn't causing the issue. You can then move your saves back too. BTW, how big are your save files? The game will be struggling with your 4Gb RAM, it has a 2Gb limit which it will reach just by opening the Launcher. If you have other stuff open on your Mac, even stuff running in the background like Spotify/Dropbox, these will use system resources. ITF, like Seasons and Pets, is very greedy and demands a lot from your Mac.