i think not putting yourself under the pressure daily of weighing and excercising may help you, even just to see a big loss at the end, the weigh in is your reward for a week of hard work.
i have a lot of weight to lose and so i am not starting an intensive excercise routine until september , i worked out if i can do 5lb a week for the next 25 weeks then i will be 11 stone at the end of september. and i think hard excercise before that will be counter productive for me. i am only on my 4th week so i am full of good intentions at the moment, but i am very determined. I know some weeks i will lose less than 5 and some i will lose more, so in september i will be doing the insanity workout and free weights (thats my plan at the moment LOL) but i was 21 and a half stone 3 weeks ago and now I am 19 and a half, i am pretty hppy with that, the annoying thing is I dont look anywhere near as much as i weigh, lots of people are even telling me i am crazy for going on such a drastic diet, its not helpful lol.
You are doing great, dont be so hard on yourself, you are determined so you WILL get there, and just think, even at a stone lighter its still a stone, and any amount less than what you were is better and a step in the right direction. we can all do this!!