Why am i so selfish? can I ever keep friends?

i don't have a lot of friends, but these few years, I have made 2-3 friends. Its quite a big improvement for me. Lately, my friend A and B had a fight. They used to be really good friends, and because I was different to them, they would make fun of me together. If I get angry they would tell me not to be so serious. And because of a fight, they kind of stop talking to each other. And I feel that hanging with one of them only is much happier and relaxing. It's not like I dislike one of them. But they are much nicer to me when the other is not around. But A thought I hate B. I told her I like B, but she doesn't believe me. I know it's very selfish but I don't want them to be good friends again. But of course it doesn't go the way I want. A just told me that she loves B again because they understand each other so much.
I don't know what should I do. I really want to keep this friendships but as soon as they become best friends, I will be treated differently. They will put each other as the most important person and I will be nobody. I know they will talk behind my back, laugh at me and If I say anything to A, she is going to tell B. and I mean EVERYTHING. She might even make things up so B will hate me because B believes everything A said. I don't know what should I do. I'm so confused now. I know that friends shouldn't be like that, but since it's so hard for me to make friends, I would really want to keep them as my friends.