Food becomes a problem when you use eating too much or too little to help you cope with painful situations or feelings. This might happen without you realising and other people in your life might seem more worried about it than you. b-eat The Eating Disorder Association will give you a lot more information.
CAMHS can help you find other ways of coping with feelings and support you to get back to eating healthily.
Talk to your GP, social worker, teacher or youth worker to help decide which service would be best for you.