Well done on a fab start! Might not be bottled, but write it all down, how good you feel, why you want to do this, what you want to change - you'll find it a good anchor point if you ever need to recharge your motivation!
Why not try one of the blogs here as a way of recording how you feel?
Hopefully your enthusiasm will continue as you lose. I've had a few weeks when it's been a pound or half a pound ... and I'm impatient enough to want to lose 5lb every week! But I am looking at this long term - even a pound a week is nearly 4 stone in a year which is a huge amount.