@MysteryKoolAid7 Yes, I would like to know where the Memory use stabilizes after you've restarted your computer and before you open anything. But the Startup tab has the more important info at the moment. Please disable Edge, Teams, and Toolkit from starting with Windows. That doesn't mean you won't be able to use them, only that they won't be running in the background on their own.
For the EA App, open the App itself, click the dropdown menu in the upper-left corner, select Settings > Application, and deselect the option to open the App at startup. This should remove the App from the Task Manager's Startup list, but double-check anyway. While you're there, it's worth disabling the in-game overlay, as this also takes resources better spent on other tasks.
I understand you have an external drive, but Windows uses the internal drive for temp files as well as the page file. You could in theory move the page file to your external drive, but this would probably have a significant and very noticeable impact on performance any time the page file needed to be used, and anyway the more important issue is lowering RAM use overall so Sims 4 has more to work with. Please make the changes above, restart your computer, wait five minutes without opening anything, and let me know how much memory the Task Manager reports is in use. I'd also like to see a new dxdiag run at that time.