i don't think it's a performance or thermal issue
Do not assume anything. As you found out last week, your laptop has some severe throttling issues, complements of Dell.
Post another round of screenshots that show how you have ThrottleStop setup now. You said your computer was running good last week. Did you make any changes since then?
Turn on the Log File option in ThrottleStop so you have a record of your computer's performance. Play a game or do something for at least 15 minutes so I can see how your computer is running. It might show some new reasons for throttling or stuttering. Attach a log file to your next post.
Some Dell laptops are like a game of whack a mole. Fix one problem and a new one pops up.