Joseph, 1200 calories a day is not very much.
You need to go and google BMR and find out what yours is (loosely) This will calculate the number of calories required for you based on your age, height and weight to maintain your current weight each day.
Like anything however, this number is just a guide to assist you when you're playing with your calorie and food intake, based on what it is you're trying to achieve (i.e. losing fat, or gaining weight).
I think you might find that 1200 calories a day, unless you're incredibly short, is probably a little too restrictive for you for long term fat loss?
Also have a read of this link. It will assist you in working out the macro breakdown you require per day. I have found that you can and should play with these numbers too and see how well your body responds to different %'s of carb/protein and fats. Everybody is very different. I respond beautifully to a carb sparse, protein heavy and moderate fat diet and the weight falls off. But for others, that may not work quite so well. So you should always find what works best for yourself.
Be interested for you to post up your current weight and height and your long and short term goals for your body.
Obviously you're trying to lose fat at the moment as your in definite calorie deficit and on a cardio intense program.
Post up what your goals are and what your stats are?
In the meantime :
Calculating your BMR :
Calorie Calculator
Also, how to calculate your macro requirements :
http://ausbb.com/nutrition-diet/15230-calculating-calories-macronutrients-bmr.html
Regardless, best of luck with your training and fat loss goals.
FYI, I'm a 5'8 female, still in fat loss mode and I roughly eat between 1400-1700 cals a day, depending on the day and the activity level. So 1200 calories for a 24 year old, active male is very low. I'm not surprised you've lost weight quite quickly.
For your long term health and sanity, it pays to educate yourself and do it the right way