Why does my older sister treat me so terrible?

My sister is 27 and I'm 22. All my life I have tried to be the best sibling any sister could ever want, but for some reason she never notices my efforts. She always treats her best friend better than me and puts her first she would rather hang out with her than me (she also allows her friend to treat me like crap), she gets annoyed with me and my presence very easily I can ask her a simple question sometimes and she will either completely ignore me or give me a sarcastic answer as if i'm stupid for asking. When we were younger she use to yell at me in front of her friends for the smallest things it could be something as simple as accidentally spilling something on the carpet and she would put me down in front of my friends which was really embarrassing, I always figured as time passed so would her childish ways but she is still the same. My grandmother has tried talking to her about this and I have to admit sometimes she does feel sorry about how she treats me and she will act a little nicer but her sympathy is very short lived and before you know it she's right back at being a *****... I just don't know what to do to gain her respect sometimes I feel so unloved and I just want to die. I don't have many friends I have more associates and I really want a stronger/closer relationship with her. We don't even live in the same state, I come to visit her every year and when she calls me for help I'm always there for her and her daughter (my niece). How can I get the respect I deserve from her? Do we need Family counseling?