My dear shalu, there is way too little protein in what you are eating! Especially given that you are exercising actively.
You would probably do much better--and feel better also--if you added more protein foods and cut down on some of the carbohydrates. You could also have a little bit of olive oil now and then--we do need to have small amounts of good fats.
I am not a nutritionist, of course, so I am simply giving you ideas from my own experience. But, if I were you, I would add some protein to breakfast--say, a boiled egg (whole egg) or some cheese--and reduce the amount of cereal a little bit.
With your apple, you could have some lowfat string cheese. This is a type of mozarella cheese, if you haven't seen it before.
For lunch you could have a chicken or tuna salad with 1 small slice of bread and some lowfat dressing, instead of oatmeal.
For dinner, you could add some chicken to your vegetable curry. You could even make something like saag paneer as a side dish, as long as you were careful about not using too much cheese in it.
I think you can see what I'm getting at. Also, have you tried entering all your foods into a program like FitDay or The Daily Plate? (They are free online.) I think you might find you are eating fewer calories than you think.
Good luck! Don't give up, just make some adjustments.