Happy Birthday Wren. BF

I just joined this forum and I can so relate to all of this. My sister is 18 months younger than I am (I'm 58) and I have tried my entire life trying to get close to her. She ignores me for months at a time, and then suddenly acts like she misses, may even confide in me about something. I get taken in and then try to share something about my life, and she just laughs and pushes me away again. It's all like it's a big joke and I'm tired of being the butt of her jokes. It hurts each time. That last time I didn't talk to her for 2 years, which hurt my mother terribly. This time my sister seemed sincere, but I've learned she isn't. I just feel rejected and left out and hurts. You'd think at my age I could get over this easier, but it doesn't seem to happening like that.