Writing in sequence

Okay, so i've written a draft of my first chapter and really need to sit down and focus on tightening and making it sparkle and catch the judges eye for content and my writing style.

So why am i busy hitting the keyboard with scenes further in the story? I can't seem to stay focused on one area. I wonder if many - or secretly all - writers have this happen to them or are they just more disciplined than me and make themselves work in sequential order faster to get to that scene?

I find i have to write the scene down when i've thought of it, or it's sprung on me while doing mundane things like folding washing, washing the dishes, and yes even changing a nappy! It's even more infuriating when i get scene flashes and conversations from my characters just as my head has hit the pillow. My husband has the knack of falling asleep practically as soon as he is horizontal whereas my mind starts to fire in all directions and i find myself scrabbling for a pen.

No matter how hard i try to get my story written in sequential order, i find myself having to fill in the gaps once i've written the big scenes. I think this may have to do with being a bit of a procrastinator and instead of focusing on the beginning i'm firing in all directions avoiding the place i have to be. I work well to deadlines so i know it will be done before the cut off for the competition but still i know i will put myself through the stress of having to perfect and rewrite a week before it's due!

Honestly, i'm seriously going to have to smack my own hand and focus really hard on the first chapter. Maybe if i set myself my own deadline, say 30 September? What if i have it written and reworked until it stuns the eyes and actually send it then? That just could work, then i can get back to the other WIP's i have going. Mmmm, bears serious thought...now on to that scene at the ballet...