Kris_blurryface Sims 3 has been out of development for over a decade, so any fixes would be on the user side: mods, different system settings, that sort of thing.
What world(s) are you playing in, and what mods do you use, if any? For comparison's sake, how does the game run with no mods in Sunset Valley?
Please also provide a dxdiag. Hit Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.