Kissyalove14 The first thing I'd like to see is a dxdiag. Click 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.
Please also let me know what changes you've made, if any, to the game's program files, for example getting your graphics card recognized or editing an .ini file or adding the Smooth Patch or DXVK. I'm not suggesting you do any of this, and in fact I would recommend not making any (more) changes until the game is stable, but I'd like to know its current state.
Separately, please test the game in a clean user folder, but specifically looking at RAM use. Move or rename the existing Sims 3 folder in Documents > Electronic Arts so that the game is forced to generate a new one when you open the launcher. You can change some graphics settings at the Main Menu if you want, but then quit to desktop before loading a new save. Create that save in Sunset Valley; it's fine to pick some random premade household.
After about 20 sim-minutes, put the game in windowed mode (but don't minimize it), open the Task Manager, and see how much RAM the game is using. If it's showing as a percent, right-click the Memory header and choose absolute values. Write down the number, and go back to the game and play for let's say 12-16 sim-hours, then check RAM use again. While playing, be sure to pan the camera over a few community lots or at least other households so the game has to load their data too, however briefly.