@RaisinsGirlELou I believe I just read an identical post over on the forums? There are several people there who are around regularly and have had a lot of success helping simmers cap their frame rates. If you give them a few hours, I'm sure they'll have some great advice for you.
I'm no expert on the subject, so I'm not going to pretend that I know how to help you, but the one thing you didn't mention doing was setting up a profile specifically for TS3 to Nvidia Inspector. On patch 1.67, I think the file is TS3w.exe; for patch 1.69, it might be TS3.exe, although I'm not sure about that. It's not necessary to do so on my computer, but I have an AMD card and have to use a different tool.
One other thing: each time you update your drivers, you should check that your settings haven't been reset, as can often happen. If you haven't done so already, you should update now, before you try anything else to fix the fps issue.
This isn't you?
https://forums.thesims.com/en_US/discussion/940101/how-to-lower-fps
Regardless, the post below is a step-by-step walkthrough of how to limit fps with an Nvidia card. Even though it's in response to a slightly different issue, phoebe's advice is great. (Actually, looks she's around on the forums right now.)
https://forums.thesims.com/en_US/discussion/comment/15362696/#Comment_15362696
Oh right that is me, when I posted on here I wasn't able to post on the sims forum for some reason but now I can. I thought it best then to leave the post here and make a new one there to make sure I get enough responses.
I've already done what's been suggested in the link you posted. I'm unable to cap the fps in both windowed and fullscreen mode unlike the OP in that link so I can't really use their post to help me ☹️
But thank you for trying to help 🙂
