Aww Sam, I know exactly how you feel. It's not like you're thinking of giving up at all, it's just your a little down in the dumps that the weight isn't coming off as quickly as you like.
I had days were I'd think "I'm so far away from my goal" and I'd get so disheartened. I'd also hear people losing 2-3lb in minimins even though they had wrote only a few days before that they went off plan for a few days and think "why can't I lose 2-3lb a week when I DON'T go off plan?"
I'm going to sound like a broken down record player but you
will get there. It might take you 6 months, it might even take you a year but trust me if you stick to plan it will fly in. Plus as you get nearer goal you'll start loving your new body. So if you've got 4 stone to go, you'll start feeling really good about yourself and your body before that - say at around the 2/3 stone to go mark. So if you're looking at the scales and thinking "I won't be happy with myself until I'm at goal" then you're wrong. As your body shrinks you'll start loving it sooner and the last few stone will just be tweaking your figure. It will come sooner than you think.
In a few months time you'll say to me "Lucy, you were right!" jut keep sticking to plan and you WILL get there. I promise. It's physics.
xxx