It sounds like a one sided friendship with this girl. If she's always negative and brings you down, you don't need her. She's probably taking advantage of your kindness and not very dependable herself. She may have some type of personality disorder. You don't need it. You need friends like Travis.

Dx: BP2, PTSD, bulimia/anorexia
Risperdal 4mg
Trileptal 300mgs
Buspar 45mgs
Ativan 1mg PRN
Vyvance 70mgs PRN