Hey hey, calm down!

It's not as scary as you might think! I did:
A: Rondo (28/30)
B: La Tarantella (27/30)
C: Adeus, Bella Morena! (29/30)
I played the Rondo at a school concert, which helped with nerves immensely (before, I could not get the sequency bit in the Minore part right at all!). If you get the chance, it'll be really good practice to play your pieces at a concert/a larger audience, obviously quite near the exam.
Don't fret too much about scales... I was really apprehensive about them, because the scale book was so long at first. My teacher suggested a method, where you write all the scales you have to do on a strip of paper, and put it all in a box. Take out a few each day and play them, then put the played ones in the lid. Carry on until you exhaust your paper supply, then start again. It helps you to not practice the same scales over and over. Also, when you think of the scales with the gazillion sharps and flats, don't think about which sharps and flats you've got to play, but which white notes you've got to play... it's easier to think it that way

I prepared for about 10 months for my Grade 5, although that's because I swapped teachers and we needed some time to get to know each other. I take it you'll be doing the exam in the summer session; you've still got plenty of time. Don't panic - and good luck!