I cant get my mind off him....HELP!?!?!

heyy. ok, well, i had or have, idkk which 1 right now, a best friend. he's a guy. we would do almost everything 2gether!!!! go over each other's houses and just hang. go get ice cream, everything that best friends would do. we would tell each other everything too. from our feelings to just funny stories, etc. i really loved him a lot. (as a friend). well, now all of a sudden he turned into a HUGE jerk. he will never respong to my txt messages. NEVER. he never does anymore. even whn i just say "hi". it really crushes me. he never talks to me anymore. its like we were never best friends. omg i wanna cry. it meant so much to me. like, my sister was txting one of her girlfriends and her name is olivia. well, he would respond to olivia's txt messages but not my sister's or mine. =[ i feel so sad. he will not talk to me watsoever. he calls me his best friend, but he treats me jsut the opposite. and i want to tell him in a nice way how he's hurting me sooo much, but i just cant find any nice words to say cuz im sooo sad and mad. i kno, usually whn you're a girl and you have a guy as your best friend, things get a lot complicated... but i need help. i cant stop thinkin about him and our friend relationship and kno that its just goin donw the drain wit him. i wonder if i did anything or.... and i kno hes a big jerk and he shouldn't be worth my time, but i just cant take my mind off him. plz help. plz. thxx