Happy does not belongs to me

Happy does not belongs to me, i am always sad. My friends didn't treat me as a friend. When they are sad, they remember me and i am the one who tried to give them happyness; when they are happy, i am always not in their group coz i am extra to them and i only bring sad feelings. But why, i did so much for wad, no meaning, to them i am juz a fly, when i go near them, they juz want me to go away, want me to get lost. I help them, they hate me, wad a funny thing is this! Just now, in school, they come and said they hate me, and they said its juz saying for fun, but i don't think so, i know this is their real feelings, how brave are they!!!