I do a lot of sport and have read a lot of books and tried a lot of methods to reduce body fat and my advice would be to (I'm going to bore the pants off you all here, sorry
)....
* Cut out processed foods as much as you possibly can, your body doesn't process the fats and carbohydrates that are in them because they've taken out all of the fibre in processing. Including Weight Watchers meals!
* Replace what you normally snack on with fruit. Eat plenty of fruit and veg.
* Cut out white bread and sugar from you diet.
* Drink as much PURE water as you can, about 2 litres a day if possible, avoid fizzy drinks and alcohol as much as you can until your holiday.
* If you are going to work out, eat more of foods which are high in protein, fish, eggs, nuts, cheese etc,
Ideally, you need to forget about what weight you are and worry about what you look like, which is what your worried about anyway isn't it? You need to be thinking about increasing your lean body mass (muscle) and reducing your body fat, you may not lose much weight but you will look better (cause you will be toned and slimmer). NO you wont be big and muscly before you ask!!
Go to the gym, don't overdo it on treadmills and aerobic machines cause your just wearing yourself out, warm yourself up on the cross trainer for about 5-10 mins, then work all your muscle groups on the machines, especially your abs if thats where you want to burn fat from, lift a weight which is comfortable (although you should be starting to struggle when you get to 10) for you to be able to do 10+ reps, start on 2 sets and work up to 3 sets when you've been a few times, do them slowly as well, slower the better. Then when you've finished on the machines, then do some aerobic exercise, your metabolic rate will be higher by now so you'll burn much more fat than you would doing these at the start of your workout.
Hoep that helps!