She's driving me insane!

I need some help! i'm at the end of my tether. My 17 month old girl is refusing to eat anything that isn't white or cream, is constantly crying and moaing about everything. she doesn't want to be held or cuddled or play or sleep or anything. and when she doesn't get her own way she smacks herself round the face and scratches her cheeks. she's never been like this and now its really getting me down. this has been going on for about 2 or 3 months and i just dont know what to do anymore.

i'm really beginning to feel like i might do something i regret. i don't want to feel so depressed all the time because i can't do anything right for her.

please help.
georgette x