I am in a similar boat. Starting a masters in cs in the fall. What resources are you using to study? I have neem doing some refreshing on Khan Academy but looking for other options.
i've been all over the place. khan academy was really good for calculus, but man, the linear algebra lectures are really long, w/ no quizzes to keep you practicing. Have read parts of multiple textbooks. Have watched 3blue1brown's excellent series. I've gotten stuck a lot and keep looking for one resource that's 'got it all', but haven't yet found it.