What do I do? How to I manage to get all of the languages straight in my head? How to I learn all three at the same time?
Well, the answer is much easier than expected. I just take everything in slowly. And I practice what I know (in appropriate situations, of course).
I already practice English no matter what. I mean, I live in America! Kind of hard to go to school without knowing how to speak, read, write, etc. English.
I practice Chinese at home (because I have to speak in Chinese to my parents).
I mess around in French. I sometimes just randomly spurt out French when I know how to say that thing in French. That's how I learn. Eventually, I will be able to use it when I need to (that's my goal). I sometimes just write it on the side of my papers. Everything you practice helps.
After all, practice DOES make perfect!