Soooooo I have about 5 full days to study for physics, math 2, and bio e. And I haven’t studied specifically for the sat IIs yet. :(((( go ahead, laugh. I’ve taken the classes though, haven’t done too bad, and im just hoping that most of the questions are more intuitive than actually content-based, the only kind of exams I seem to be good at.
I have 2 interviews tomorrow, so maybe ill get 5 hours to look over some stuff, and maybe 2 hours total per day for the next 4 days (I have swim practice, and i already know the coach wont let me off, plus 2 finals in school)
How to best continue? Any internet-based (or otherwise) absolute last-minute musts?
The best advice I can give you is not to stress yourself out. At this point, there is honestly not much you can do to boost your scores a ton, so go in knowing that you’re prepared from taking the course. Know that this is not the end-all be-all and you can always retake. Also, to be realistic, your SAT I scores are not always indicative of your SAT II scores, so if you do not feel confident, maybe study more in advanced the next time you take it. Best of luck! 
Do you absolutely need to take all 3 on that day? On the day of the test, if you don’t feel prepared, leave one out. For math 2, I suggest reviewing formulas like the conic section stuff. Biology, just skim through Sparknotes or something. Physics is probably also formula based.
Good luck.
Like CCClassof2019 said, just go through sparknotes. I spent my time playing PA mid the entire week before my SAT II and prepared from spark notes only the morning before the exam. I happened to score M1-800,M2-800 and P-790, so I think I am a bit qualified to tell… GLHF.
Mid or Feed,
Q.