I know exactly how you feel, i've just finished school and i'm looking for a little summer job, i've handed out hundreds of CV's to cafes, small retail shops, and even some of the bigger shops such as next and river island and not a single one got back to me!
i honestly thought people would want to take younger people on seen as you don't have to pay us as much as say a 19 year old, with the minimum wage paying less for younger ages.