Lovely horse, you really need to work on getting a good balanced, correct, canter before attempting to jump though which is why your horse struggled a little with the 3ft. You weren't very well balanced with it either, and on the little 2ft fence after the double you tipped forwards.
Relax when youre cantering too, rather than banging on its back. You jumped the 2ft6 spread nice.
I thought for gcse horse riding you had to jump a course of 3ft, rather than just one fence (although it's been many years since I did mine).