braces, feel like I'm not me anymore, WANT MY LIFE BACK!

I think I know that I have a problem, confidence and depression at the same time. I am 19 years old and a second year international student at a university in UK. For the first time in my life when uni started I was full of confidence and I wanted to meet new people, going out, having fun with friends, for the first time I felt happy. happy, what a nice word, what a nice feeling. During xmas holidays when I came back to my country, I needed to put on braces again. ( I used to wear for three years in high school, and then it took me 3 more years to recover for all this judgement, you know I was the girl with the braces). and now, going back to the beginning. Since I put on braces again, I feel like my life is destroyed. I feel useless and ugly, I don't want to go out, I don't want meeting new people, I don't even want to go for a coffee. I am just in my room. While I am studying I might start crying and being nostalgic and miserable for those 3 great months that I lived. and now is all gone. I feel like my life is destroyed...I know there are more serious problems, but I just can't..I feel sad, so sad