Fruitfreak you don't need to worry about losing weight it's fat you want to lose.
My point is that I wouldn't suggest you measure your progress with the scale, at all.
For exercise - there is no "best exercise". Given your relative lack of time I would suggest looking into something you can do at home so you don't have to spend any time going somewhere to workout.
I'm personally a fan of "Spartacus 2.0" workout which requires only a small investment in weights. Wallmart sells a very cheap weight set which would work for it.
Having said that - what matters is an exercise that you enjoy or at least don't hate so you incorporate it as part of a lifestyle.
Finally, I usually don't have a problem with people's calories being too low but in your specific case I would advise you to increase your daily calories. Not by a huge amount but you should be able to lose fat at 1500 calories and always lower them in the future.