Dear Katie,
I don't know if I can say anything that will reassure you or build or confiendance. I think what you are going through is somewhat natural, lets face it , we all want to be more attractive, for different reasons and one of the reasons , I myself would like to be more attractive to fit in more, to be more accepted by people( I won't go into all of the details about that) To want to be more attractive , to want to have a perfect body( or atleast your idea of a perfect body) is not overly wrong or unnatural as long as it does not become your obsession . I can understand what you are going through because I myself has put up with a lot of mistreatment because of my physical appearence and still do( I had someone once tell me that I was never going to have a good job, not because I lacked any job skills but because of the way I looked/ my physical appearence, and so far , that has been all too true, unfortunately, so you see, things could be alot worse) I try to deal with it by being grateful for what I do have rather than focusing on what I don't have. Be grateful that you have two arms and the ablity to walk and talk. Be thankful that you have friends and people at church that support you.., even if you have just one friend, you have alot more that I do.
Also , I don't know if this will work for you , but for me , I like to think that in heaven that I will have that body/ physical apeearence that I always have dreamed about, not that looks will really matter in heaven but more or less that GOD likes to see me happy and enjoying my self and beleive me GOD knows that I would like to be far better looking than I am( mainly because of the mistreatment I have had to endure in this life because of the way I look) . Again , not because He has too , but because of the joy He gets to see me happy, or atleast thats what I like to think and thats what I would like to happen. I like to think that heaven will be a place of perfect beauty and that our flawed bodies will be more perfect in heaven.
But lastly and most importantly, when you are feeling down about your physical appearence, chance the subject of your focus, in other words , focus more on GOD rather than yourself or pick up a book and start reading it, anything to keep you from thinking poor thoughts about yourself. I hope this helps .