i like going places too...

So my entire life I have been invited everywhere my sister goes to hang out and watch her step-daughter, but now all of a sudden I am not good enough to go with her. She made a new friend and so now I'm never invited to parties, the movies, or even just outings. I feel like I was being used all this time. I am so lonely, my only friend is 12, my family doesn't want me around and my boyfriend never really wants to go anywhere. How am I supposed to get better when I'm alone....