Sims 4 Castle kit bug

I purchased and installed the Sims 4 Castle kit 3 days ago. Ever since I got the kit, I've been facing extreme lagging in my game. It only appeared to happen when I was in building mode, specifically when I was applying the new wall paint , from the castle kit. The first time I tried to apply the new wall, the game froze, then load for a bit and then it totally crashed. I hadn't even saved the game, I lost progress from building and designing an entire castle.. So the second time I opened the game I saved the game with every little update i was doing in the build. However, at one point, once I clicked on save, the game froze and stayed on "saving" for good 30 minutes. I had to manually go to task management window and shut the game down, knowing that once again I'll lost my game.I decide to open the game for the third time, but only 3 minutes into the game and it crashed. Completely closed, it brought me back to my windows screen. I feel like at this point the game has become unplayable, I don't know what to do. Could it be that the latest sims update might have caused it and not the castle kit? I have zero mods in. Please help, how can I go back to my game. Thank you.