How do I cope?

I have a friend and we have been friends ever since we were 3 but in the past year or 2. I really don't know how to cope. So me and her where having a sleepover and she said that she had a boyfriend. I really don't know what to do. I feel so heart broken. How should I cope. I don't know why I love her and I am pretty sure I am in love with her can anyone help me understand. 😥😭🤕🤐