Is it a good idea to just end the friendship?

[Gloquet]

That's how I feel with my friends. They are always together, and they would make me tag along behind them. I felt like I was just a back-up friend for either of them, to be there just so they wouldn't feel lonely even though they left me alone many times before.

Try to get some other friends whom you know will never use you. Then if Anna comes running back to you again, help her also. If you feel like she could still be a good friend, just try to hang on for a while and be there for her. But if ever she will just use you, then ignore you again, confront her about it. Tell her how you feel. If she stops using and ignoring you, then she is a good friend. But if it will really not get in to her head and will just use you again, she doesn't deserve a good friend like you. No one deserves to feel like a third wheel.