Playing Sims 3 on Mac, crashing randomly

Hi everyone, I have been playing sims 3 on my macbook air. I only have 1 pack, no mods, no cc. I am having lagging and input issues when first loading into my game, then it goes away eventually. But, my game is randomly crashing. No glitching before hand, either freezing out of nowhere, or the app just crashes itself. I havent tried any solutions yet, as I didnt want to mess with it, if its not the right issue. If anyone could help me, that would be awesome. Hating having to save every 5 minutes lol.