please, please help,i think i might have an eating disorder?

I am 17 years old, and I know it might sound stupid to other people who read this but, I think I have an eating disorder. I have always had pretty bad self esteem problems, even when I was very young. Because I grew up going to a school, or schools, because I moved around a lot, and almost all of the pther girls were all blond taller and and skinny. Of course not all of the kids were like that but, the ones that were considered pretty were. I was much shorter a bit chubby with brown hair. I was picked on all the time because I was quiet and shy. I am now 5'4 and I unfortunately weigh about 112 (yuck). Last year I said to myself, okay I'm tired of not feeling comfortable with myself and how I look, so I'm just going to shut up and do something about it. so, i became vegan, i lost the weight, in a way that i knew was unhealthy, under 600 calories a day mainly, i started counting calories furiously, and much to my pleasure it worked. I went from 130 pounds to 100. Then, about five months ago, I had a viral infection, and severe dehydration, and I got down to 87-98, so I had to go to the emergency room, and when I got out my mum said, i should start eating healthily, and so i think i got a bit caught up with that notion, now im up to 112 pounds, but it fluctuates. i can't say how bad i feel now. even though i know im not fat... i feel like im becoming the old me. i felt much better when i was smaller, and since i have a petite frame, it shows to me quickly whenever i gain... and its driving me crazy. all ive ever wanted was to be pretty, and it's becoming even harder than it is to begin with, to accept myself. i don't think i will ever be happy with how i look. even though its mainly my legs, it's a face thing. i have a slightly round face, a button nose, and what i see as a crooked mouth, even though other people say im very pretty, i just see this ugly thing whenever i look at myself. i feel like everything about me is just, off. and to top it off, my mother (who is my best friend), is gorgeous, so thats all ive ever had, my entire life, is constantly being compared to her. its definitely not a jealousy thing, because that would be weird, but its a constat inferior feeling. i never feel good enough. and ive never had many friends, or a boyfriend, so i spend quite some time alone. but i just never feel good enough to please anyone. things are just starting to get really hard, because i feel so out of control when i eat. i always manage to stay under 900 calories, but whenever i go over 650 i feel like this undisciplined loser. i do have a family history of eating disorders, bu i love being around people, but i just am so used to a feeling of rejection(im told im too sensitive), and i really would like some help. i just feel so alone with this, and obviously i am young, and i know this is going to sound stuoid, but i would just like to hear from someone, that im not alone... also, last night i told myself that today i was going to try again(foodwise) because i had to go to a dinner last night, and i normally dont eat dinner so i felt really guilty about it, but today i just had a few bites of pasta as well as my apple and rice cakes, so im feeling very crappy about it.

anyway im sorry this was such a long read but i didn't know how else to say it... so if anyone could help in any way, that would be lovely...i just really dont know what to do. my parents have tried to help, but theyre under a lot of stress and pressure as it is, so i just feel so selfish, but i cant help it...