My advice is to not incerase the exercise but to increase the food! You really have to eat more.
1000 calories a day at that level of activity is not sustainable and your body think it's starving itself so it's hanging onto the fat for dear life.
Get onto a site like myfitnesspal.com and you input your details and it can give you an idea on how much you should be eating.
There is also this site .. http://www.fat2fitradio.com/tools/bmr/
.. put the details onto that page and it will give you your BMR and will give you an idea of how many calories you shoul be eating. It will give you a shock as I wouldn't be surprised if it says you should be eating over 2000. If you did start eating at that level it would take your body a couple of weeks to get used to it and then it will realise that it can start getting rid of the fat (and the omega pills! )