Kushina9999 we need more information than you've given. Could you be specific about which platform you are on and if it's PC are you using mods?
Some things that can slow your game down would be carrying a lot of items in the personal and household inventories of previously played households, having excessive households in Other Households, having a full library, having a lot of save files. These cause a lag in particular on console. Playing on an older console can do the same. I'm on Xbox Series X with all packs and my game isn't slow, except that loading screens are taking slightly longer since adding this year's new content which is to be expected for the size of the game.