What did I do wrong?

I try sooooo hard to be there for my friends when they need me.

I listen to them and try to give the best advice I can, I care about them and try to make sure I dont hurt them...I wait for them, adjust my schedule to theirs, sacrifice things to hang out with them, text them back immediately when its something important, listen to them vent, vent to them when they want me to, tell them what they want to know...

Yet, when choosing between me and another friend, they will always choose the other person.