I need help ..............................…

i think im phsycologically sick. I fell in love with this boy and i tried to know in a way if he likes me and i found out that he is not interested. I just want to forget him but the problem is tha my love for him is gettin stronger day by day . help im 17 i jist cant forget him i think about him day and night for years and when i see a movie i cry like an idiot bec it reminds me of him please help me