You have a nice 'snap' at the end of your action, and seem pretty nippy! As Dean suggests, perhaps get some poles, or even try to bowl off a few steps, making sure you keep your form, but when you are bowling like that, I would recommend keeping the pace pretty high and snap and follow through fully! (It's easy enough to keep form when bowling slower and not following through fully) I'm guessing Brett Lee is one of your favourite bowlers. 
Haha you guessed right, i wonder what gave it away, surely not the gather ? xD Thanks, ive noticed that of a jog, i fall away a lot less and are pretty much upright, but when i go back too a full runup i fall away, though, it has improved a lot ! i used too have lower back pains due too a mixed action and the amount i used to fall away, ive become more upright and sorted out my action since then and put on a lot of pace, this is my first season of cricket, i started at the end of last season, but im still not upright enough, one thing ive noticed though, is when bowling the bouncer or back of a length ball, i am a lot more upright, kinda intrigued as too why that is, and the fuller the ball, the more i fall away.