Why does my older sister dislike me so much?

Well...basically...she is 17 years older than me...i'm now 22 and she is 39...ever since i can remember she has always disliked me, and I have no idea why. I thought she would be more like a loving caring motherly type of sister since our age difference is so large, but instead she just acts like a total b**** every time I seem to be around her, which is not often at all since we are not close at all. She is the only sister I have and it saddens me that I have never know what "sisterhood" feels like. She always goves me dirty looks, or she can never agree to something I say, I honestly don't know what the problem is but i cannot recall one "happy" memory with her where it was just the "two" of us doing something fun. I'm kind of sick and tired of trying to figure out why she can never get along with me...she doesn't even tell me why when i ask...and sometimes well now that i'm 22 i just really don't care anymore, but sometimes it saddens me and it makes me ask myself over and over why my big sis dislikes me so much?...well thats about it...i just can't seem to have an answer for this myself...oh and it also seems like the only time she's "nice" to me is when she wants me to carry around her bags or go with her somewhere because she has no friends, so i'm like the last resort...but even then she'll only act nice for like the first 1/2 hour...pathetic...she should act her age!...and u know she doesn't have to be my friend but at least have some respect when i come around her, which is usually just because of my parents and our gatherings...