Study Help/Advice Required!!?

Hi Guys, So here's my Situation I left High School In 2009 With 1B 4C's and 3D's and am now in my second year of 6th Form, and have so far recieved BDD. My concern is i am picking up AS Music this year with GCSE Maths (To boost it to a C or Higher!) along with my A2 subject which are: English Lit & Lang, Media and I.C.T. The problem i have is that i only get about 4 free lessons a week to study my backside of as this is the important year for me as i'm going to apply for University. The problem i have is am i doing to much? What degree should i consider doing, with my goal being to become a Primary School Teacher which is why im working my backside of. But i also have a saturday job which is 9 Hours which i hate which means i only get sunday as a full day off which is spent studying. Should i give this up and focus on Studying? the only Con against this is that i am learning to drive and have had 15 hours and ped my theory test with 48/50! I recieve the full EMA limit weekly so i could manage driving. Can somebody please help me with some reasonable advice!!?