How do I manage Junior Year of High School?

So I start my Junior Year of high school in exactly one week from today! I'm taking 4 AP Classes, and 4 Honors Classes. I have no lunch, study hall, or off period. I am going to go straight through the day from 7:00 am to 2:30 pm with no breaks. I am taking AP Lit, AP Chem, AP US History, and AP Euro. I am also taking Honors Pre-Calculus, Honors Spanish, College Criminal Justice/Sociology, College Accounting/Wall Street, and Weight Room. I am involved in three clubs, my most demanding being the Mock Trial Team, where we have practice Monday until 4, Tuesday-Wednesday until 5:30, Friday until 4, and Saturday Morning from 8 am until 12 pm. Also, I have an SAT class every Thursday from 5:30-6:45 about an hour away from my house. I work on Sunday morning from 8 am until 3 pm. On Friday night I volunteer for a local government from 3-5 pm. Also I have three tutors for an hour each every week. On top of this, I also play the piano and take an hour lesson every Monday, and am prepping for the National Piano Guild Festival. I don't know how I can balance all this plus my school work! Finally I am the Vice President of my high school, and the President of my Class. Please any advice would help!! Thank You!!!!!!!