@nviiw Your dxdiag is full of errors of what looks like a component of IOBit software, so if you use its antivirus, please set exceptions for TS4_x64.exe and Origin.exe. Please also test in a new user folder: move the entire Sims 4 folder out of Documents\Electronic Arts and onto your desktop, and when you launch the game, a clean folder will spawn with no content. Don't add anything to it yet; just start another new save and see how it runs. If it's fine, you can move your saves and other content to the new folder and test.
If that doesn't help, please look for any Sims 4-related errors in the Reliability Monitor. Hit Windows key-R and enter "perfmon /rel" without quotes, and you'll see a chart of errors and updates with a column for each day. Today is on the right.
For any errors that list Sims 4 or Origin, or any that happened while you were trying to play, right-click on the error name and select "View technical details," then copy the info and paste it into a reply here. I'm only interested in errors that happen in the new Sims 4 folder, as described above. If you don't see an error but fps is still low, that's useful information too. The Reliability Monitor only updates once every hour or two, so you may need to check back later if you've already opened it recently.
And don't worry about the late reply. Someone is always here to help whenever people are ready.