Why am i not losing weight?

i eat healthy (maybe 1600 calories or less a day), im about 100 lbs overweight (so it should be easier for me to lose weight), i do about a 500 calorie burn workout a day (for 6 days). I've been doing this a month and i've only lost about 2 lbs a week. now i know some of you will say that is normal but i have been working out extremely hard and i know its possible to lose more than 2 lbs a week (its been about 3 weeks since i've been consistently working out). I do some strength training so i know that helps build muscle so im not sure if that is why i haven't lost as much. i don't drink a lot of water a day but i drink a lot of crystal light (which is basically water). im not sure what the problem is.