Make some really small changes if you can.
If you take sugar in coffee/tea then use sweetners or nothing.
Do not eat any breakfast cereals, they are crap. Make sure you have porage or bacon/egg, somthing decent for your brecky.
Cut out refined foods, try and eat brown rice/bread/pasta.
Dont ever buy sweeties/chocolate. If you get some for birthday/christmas thats fine but dont go out your way to buy them.
If you are doing all that then you may need to make more drastic changes.
Good luck. i started my journey this time last year and have lost 2 stone, but still have 2 stone to loose! My focus is on getting fitter and just trying to eat good food, the weight reduction is slowly taking care of its self, but i monitor it every week to make sure im about on target.