Step one is to talk to your guidance counsellor at school. Step two is to see your family doctor. I'm not sure the rules there but here 14 is the age one can see a doctor and be in charge of their own healthcare without family involvment. The counsellor at school may be able to help set that up for you. They should also be able to act as an intermediary in getting your family onboard with understanding and treating your emotional health.

Thank yourself for making the step of asking for help. So many of us suffer alone until and through adulthood (I was 45 before I got help).