Why am I always trying to change myself?

I reciently read a post on my friend leahs blog 'stereotypicality' and something hit home. I don't think i have ever got through a day, or know any girl who could truthfully say they have, without wishing something about myself was different. I wish i was thinner. I wish i was tanned. I wish i had more friends. I wish i was more confident. I wish my hair was longer, and blonder. Additionally, as leah pointed out, i cannot go out without makeup, to change my skin complextion, to highlight my cheakbones, to make my lips fuller and my eyelashes longer, and this makes me fake. I think there are very few people who really know who i am, stripped back. I am also a hypocrite when it comes to this matter, i reciently posted about people and their profile pictures, when i activley look through new tagged pictures of me, seeing if theres one i like.
Why do most girls want to change themselves? I can look across a crowd of people and instantly pick out a group of girls who i would rather look like. What makes this more pointless is that the girls i would pick, probably could do the same across the same crowd, but pick other girls. What i'm trying to say, is that i am going to recognise that most people really aren't that judgemental, and have their own insecurities to worry about.
I know that i am not the uglyiest person in the world (feel free to dissagree), and i know that i am not 'hot'. I wish i could just be comfortable in my skin.

I appologise to anyone who actually reads this that i haven't been able to post in a while. Sinse my last post; my GCSEs have started, I had my last day at school, and I have asked a friend to prom.
I have been going stir crazy over the past couple of days, forcing myself to stay in and stare at my revision notes. I have also been cut off from facebook and the internet in general, because my laptop covieniently broke just before my first exam. I have my suspicions that this is a plot from my scheming muma inorder to keep me focused.
I went to see the new Pirates of the Carabian film yesterday. Well, I saw Jonny Depp looking hot dressed as a pirate. To be honest in not sure what happened in the film, except that he was in it. So, it was good, i deffinatley recomend it.
I went to the doctors reciently to try and sort out my hayfever and skin before my exams and summer, and came back with steroids and the pill. Not sure that he understood. Anyway, this was part of my desperate attempt to look half decent for what i hope will be my best, most eventful summer so far. Alongside the skin regieme, i am attempting to loose weight and tone up, however i am finding this rather hard. I try to go the the gym twice a week with my auntie, however sometimes, frequently reciently, she is not able to go. Now this would not fase a normal person, but i am not. I get intimidated by the huge strong guys who appear to live there, and only eat raw meat, and the scary thin girls with blond shiny hair, who run wearing short shorts and a sports bra, and manage to get through the entire session without producing one bead of sweat. For this reason, i do not find myself in the gym, by myself very often. Staying at home during the week doesn't help either. I find myself gathering remains, wrappers and plates of food around my 'revision zone' that i do not remember getting from the fridge or let alone eating it.