Is there anyone at school you can get advice from, a counseling center or something? How long have you felt you have had these problems? It could be that your parents noticed earlier but they did not want to "see" and did not mention it, hoping you would "grow out" of whatever behaviors. Have you looked at ways to help yourself, read any books on the subject, for example? I think OCD in Europe is viewed differently than here in the United States: An Epidemiological Perspective of Obsessive-Compulsive Disorder in Children and Adolescents so you might want to do some more local readings to see what it "means" and maybe how you can better ask for help?