I am to the point where I am exhausted. I have a child with no diagnosed issues, that lies and gives general attitude, however to the point she is ruining lives. I am almost to the give up custody to her father point because I am so emotionally and physically exhausted.
You are in a place where we understand! Dealing with our difficult children is not an easy path. Often we need to change our outlook and look for the behaviors that are a result of issues they are dealing with and mostly outside their control (either because of their issues or their maturity).
Is your daughter undx'd because the docs haven't found anything? Coming here is a step in the right direction because many of us have been at the bottom of our ropes with another 25 feet below us!
I suggest you create a signature to give us a little more information on the family situation and what has been tried with your daughter. Usually we have more questions for new members than answers until we get to know the situation a little better.