Don't forget the GMAT Prep test -- take that in the beginning so you have a sense of the types of questions. Save the second GMAT Prep test to take some time in the last 1-2 wks before your official real exam.
The OG sources you listed are a good list -- those are the official questions. Be careful if you run out. Ideally, those questions should be enough. And if you're still not 'getting it' by the end -- you may have not found any framework strategies that help you. Try to avoid that. Learn your strategy and refine it over time as you go through these questions. That said, if you need more questions, try the practice pill platform from gmatpill -- a good community of Q&A going on so you can understand why correct answers are correct, etc. Hope that helps.