Body image

I've only just joined 7 cups because recently I've been struggling with very low self esteem. I just seem to always be comparing myself to others and I get really anxious about my weight, even though I am an average weight for my age ( I don't want to be heavier than all my friends!). I've tried lots of different workouts and even restricted my diet but nothing has worked. I'm also very self conscious about the way my body looks- I feel so chubby and bloated all the time and I especially hate my thighs. I was wondering if anyone has any advice on how to lose weight fast, and how to be confident about the way I look? It's so easy to say that I don't care what other people think, but I really do :(