Hi,
I definitely understand the desire to lose weight rapidly... it gives you the motivation and determination to continue working hard when you see the results. The worst feeling is eating right and exercising and not seeing the scale move.
1400 calories a day is not enough for me - I'm a moderately active, 5'9 female. I aim for 1500-1800 calories daily.
I think the best way to lose weight fast is not to reduce your calories - "starvation mode" is a bad place to be. Switch to mostly vegetables and lean protein - cut out processed foods, sugar, dairy, red meat... etc. It is more difficult but it feels great to eat really clean for a couple of weeks.