Hi Rose - one thing that is important is that you don't eat late. Usually I have my dinner before 8 in the evening so it leaves time for it to be digested before I go to sleep. Even if you are not into exercise even a simple walk can make such a big difference. Will you new job involve a walk at all (eg. from a train station to your workplace).
One thing that I think is important is that you don't beat yourself up if you do have a biscuit or a bit of chocolate every now and then. If you try to cut it out completely then if you do have one you will really beat yourself up about it. Obviously do cut down on it, maybe one bit of chocolate after lets say 4 days as a reward for going that long without it?
I hope you won't dismiss this because I'm an exercise nutter