I love a person but its onesided?

at the beginning he replied all my messages but when he got to know that i am falling in. he behaved very rudely from then to up now he always insulted me . i find him polite with me once in a blue moon. i cant leave him and now i have done my studies there's only one way to communicate thats his cell no. but still he donot reply what should i do i cant forget him.i feel gloomy i really miss him