Hi, greetings. I can understand that white hair in young age could be traumatising and socially in appropriate. It could be due to certain hereditary factors or it could be due to hormonal imbalance or vitamin deficiencies. You should see an approachable qualified dermatologist and take his opinion after having discussed the possible causes and necessary blood tests being done. Oral anti oxidants will be of some help. In long term it may be advisable to use a chemical free dye . hope this helps.