Flickering in build a sim

Hey, i started playing sims about a month ago. And recently I just got it on my Mac computer. 
the other day I bought the parenting skills pack and after that my “making sim” option (where you dress them up and so on) started to act weird. the screen starts flickering in rainbow colors. Especially every time I click something like the little cube. I use mods yes, but I have tried everything. Every removing all of them and refreshing my folders. I tried to look for help on tiktok and YouTube and my only option now is here. It doesn’t happen as soon as I close the sims 4. Only when I play the game. 
Is it my computer? 
Keep in mind. My computer gets really hot. Does that have anything to do with it? 
it just haven’t always been like this and it’s so tiring because I just bought the sims 4 and it’s already messing with me.