I don't like that two of my friends are friends with each other
Why do you not like that?
I'm afraid they will start talking together about me as an annoying person and I'm afraid I'll lose them both as friends.
You should accept the fact that those friends are friends with each other. You cannot control who they associate themselves with.
I feel hurt and I feel like I'm losing them one by one.
Your friends have the right to be with whoever they want to be with and your paranoia over them talking about you behind your back is going to ruin your relations with them. Get some professional help to address your deep-seated fears instead of projecting them on to your friends.