I need help with universities :/?

Hello there, I need some help. Basically i am currently doing my a levels and in the lower sixth, however im worried because i really want to get into a specific university (Durham) to do Geophysics, but i need AAB. I have tried the best i could possibly do so far and i got 2 C's January which i was really really upset about and my upcoming exams and pretty dam hard :/ im really worried because this is what i want to do for the rest of my life and durham is just perfect. i work so hard to get higher grades. I do maths, physics, chemistry and geography. my january module in maths was weird because it was rather alot harder than previous years i had completed all the past papers and got mostly A's in all of them. physics is stupidly hard cuz they can catch you out in such little places. I just wondered what can i do? i really dont want to have to do a different university course at a different university because i know for a fact i will just drop out due to being not intererested.. is there anything i can do to maybe get a place? a few people have mentioned because of the new 2012 system there will be alot less competition to get into those universities. im aiming as high as i can physically do i just dont know if its high enough. I also do EPQ on geophysics and open university course on tsunamis, earthquakes and volcanos. argh this is frustrating!! Thanks for reading.