My grades are so bad...please give me advice?

I am a junior in high school and I was always a good student. I had straight as my freshman and sophomore year taking challenging classes. I am now a junior and my grades stink! Although I am getting an A in English, Pre-Calculus, Health, and Spanish my Physics and AP US History grades are Bs and I have a C in microbiology. I literally balled my eyes out once I got my progress report because I am not used to getting these type of grades at all! I am taking two advanced science classes this semester and I have just been struggling to stay afloat. My microbiology teacher tried to reassure me that there were only 3 grades on my overall grade and me failing the quiz caused my grade to go to a C and that there would be only labs the rest of the semester (which I do fairly well in). My test corrections for physics and APUSH would bring my grades up, as my teachers tell me but I still feel like I have so much on my shoulders. I cannot even properly study for my SAT now because I am so overloaded. Please can you give me advice to help me get through the semester without tarnishing my straight A high school transcript.My grades are so bad...please give me advice?
I just read this book called ';The Organized Student,'; and maybe you need to take a moment to breathe and organize everything that is going on. Maybe you are more stressed and your grades are slipping because now the pressure is on, with the SAT's going on and with thinking about colleges and the future. On top of this, you may feel worse because you feel like you have no control over what is going on. Find organizational strategies that work for you: lists, calendars, planners, post-it notes.





Hope you keep up the good work!My grades are so bad...please give me advice?
This advice is for all: make time to study. If you haven't done this trick, then it could be the trick. Get a daily planner book. Write out the most important things first, then prioritize what time is made for study time for each subject. The classes that you want to work on should get top priority but not as much to have the other classes suffer.