What's Happening to me?

I'm 19 years old and have had my period since I was 10. Then 5 years ago I developed anorexia nervosa and have been struggling ever since. I never lost my period though, even though I've stayed either underweight or severely underweight over the years. About a year ago I started taking Alesse because I couldn't stand how my period was so irregular- I sometimes got it twice a month. Then I discovered I could stop my period if I only take the pink pills and then go straight to a new package. Now before you say I'm stupid for doing this understand that it's obvious I'm not all there by the medications I take. ;-) This is just another way of coping with mental health issues.

So anyway, what I'd like to know is why am I spotting so much now? Is it because of my anti-depressants/anti-psychotic medication, the birth control, the irregular use of the birth control, stress from anorexia, or what? Cuz I read up on what spotting means and there are so many possibilities. I don't know which one is doing it. And I'm too embarrassed to bring this up with my doctor (he's male). Technically, I shouldn't even be getting my period. I hear everywhere that not eating right and being underweight can cause you to lose your period. I am anemic and vitamin b12 defficient and I also have osteopenia-- so these are proof that I don't eat right. So why are all these parts of my body shutting down but my period is going strong? Or is the spotting a sign that it isn't going strong?

I'm so confused. ?