Getting my period every 2-2.5 weeks?

Hi,

I'm 16 and since the month of March I have had the strangest changes in my cycle...I know periods are supposed to be irregular until I am a few years older but in all honesty for the past year up until March my periods were always regular, I never had cravings (like maybe once or twice in the past 2 years did I get cravings) and my mood swings or hormones never went that crazy other than the occasional sob fest and depression near the end of some of my periods.

But lately, since March (or maybe February can't remember exactly) things have changed. I started getting a lot heavier periods, I'm a lot more tired (I used to actually exercise best on my period but now I'm very lightheaded and can barely go for a walk the first few days of my period due to the loss of iron)..I do have a problem with not enough iron in me, I try to eat as much iron-rich foods as I can and take multi-vitamins. I get the WORST food cravings. God, I have never craved chocolate so much in my life as I do the few days before and during my period. I gain so much weight, and I don't really bloat, so I know all the weight I gain is from all the junk food I hoard in my mouth. I mean I seriously never eat like this! But on my period I literally just don't have any control over my cravings and I just grab carton of ice cream and dig in until the box is empty..Also, my periods, since March, have been occurring every 2-3 weeks! I can't take it, they hurt too much! Like right now I am starting my period yet again, and I just got over my last one a little over 2 weeks ago.

I have a little "theory" that the reason this is happening is because of my change in diet. Since the beginning of March I've lost about 10 lbs (I am now at a normal, healthy weight). I work out 4-5 days a week (a couple days of some cardio and a couple of some circuit workouts) and I eat a LOT healthier, I mean looking back on it I probably ate near 2,000 (if not over) calories a day, and now, I check food labels a lot, count my calories, and allow myself to only one or two "cheat" meals a week, that way I keep my mind on track. I don't have chocolate a lot anymore, when I do it's usually a pudding cup or a granola bar. I used to eat pasta almost every day, and now I only eat it once every 2-4 weeks. I think my period changed and became more frequent because of my change in diet, and my mind, or hormones or whatever, crave the junk foods that I have "deprived" my body of, that's why I'm getting intense cravings. Can anyone help me? Thanks, sorry this was a bit long.