Please stop smoking to fit in with your so called friends, they are not your friends and it will take you 30 years and a whole load of money before you manage to stop.
You are not fat, you have a lovely hourglass figure, which will never look as good as it does now, wear a bikini while you still can. Ditch the baggy jumpers.
Being clever is not a bad thing, you were born into poverty and lack of aspiration, but it will help you get out of it, don't dumb down just to fit in.
Please don't get that perm you are considering, it will never suit you.
Do not accept that date to a gig with him, it will lead to 7 years of abject misery that will cast a shadow over your life well into your thirties.
Leave home as soon as you can, your mother is not your friend, she only likes people when they need her and are pliant, she will never celebrate your successes, only your failures.
Dont stop playing your instrument because its not cool, you have a talent, you will regret not continuing when your older.