my sims game keeps lagging, and wont save

So, every time I load up my game it goes perfectly fine, all of my mods are updated and I even got rid of a few that I thought could be an issue, but after a few minutes of playing it lags when I'm trying to switch between sims, or even if I go into build mode then back to live mode. It won't even let me save the game when it lags like that, I have tried to repair the game and everything, but I really need help because every time I switch between sims it lags, and it won't shot all of their emotions or just stay highlighted on one sim even though I chose a different one.