I've been eating 866-1200 calories a day for a couple months what effects can this cause and is it already effecting me???

Alright so in the past couple months I have been eating between 866 and 1200 calories a day
And I'm just wondering what the side effects from eating that little calories can be???

I already notice I'm tired everyday and often feel like I've gotten no sleep
Like last weekend I slept 12 hours but still the next day felt like I had gotten no sleep all day.
Then yesterday at school I was so tired I felt like I was going to cry for no reason.
Plus I have some sort of cold right now. Stuffed nose none stop coughing that only makes my throat hurt. It's like a tickle in my throat that forces me to cough and when I cough one I cough a bunch of times and every time I cough I see green swiftly lines at the edges of my vision

Anyways my question is how will eating little calories effect me??? Is it already effecting me???

I am a female and am 16 years old if that helps any

Also my mum and family keep telling me I'm to skinny or I look to skinny but I disagree I think my stomach is qite gross and I should deffently lose the last 7 pounds of my goal. I am 5 foot 10 and 139 pounds I was 156 last June but I decided to lose weight and now so far I have lost 17 pounds and have 7 more pounds to go. Even then I have 2 more goals on top of that goal once I reach 132 I'm going to try for 128 then once I reach that I'll aim for 120 then maybe 115
I know those are stupid goals and I'll look like a rack of bones which I don't want but part of me doesn't care it like losing weight it LOVES losing weight. Just the other day I told myself I don't care if I go underweight at least I'll be skinny and beautiful and have a flat stomach even though I know going to one 115 I'll just be bony I'm stubborn and once a goal sets in I don't like to stop until I reach it. I know I should just the goal but I can't I dint know how to. But I'm tired of people telling me I'm to skinny. But I can't stop.

Advise please

I don't know what do you think???

[Bran_Bran]

Please someone I would like someones advise I've been getting obsessed with calorie conting the past few days one day I only had not even 600 calories and I still felt like a pig for having a cookie and a small cup of milk with the cookie (before the milk and cookie I had only had 525 calories) I know I need to eat more but I find food extremely depressing and can't bring myself to eat more that 1000 calories a day and if I hit 1000 calories a day I freak on myself. And I appsalutly hate it how most nights for dinner I can't tell how many calories in dinner because my mum makes dinner.

Anyways what can eating so little caories do to me??? In long term and short term??? Because I can't help but to try and as little calories a day as possible and I want to know how it's effective Menander how it will effect me???

Thanks for your input