What do I do if I have a twin sister and I cant get into any relationships because of it?

Hi!
recently I've been getting real frustrated because people think I'm exactly like my twin but I'm not.
For me twins are like magnets sometimes they repel each other and sometimes they just won't separate. I think that in our case we repel each other (don't get the wrong idea it doesn't mean I don't love her)and I guess guys don't dare come near me cause my sister is a bit immature and jumpy and mean when she dislikes someone

What do I do to stand out?