I am undone.

In Perek ו Passuk ה Yeshayahu explains his experience in seeing Hashem. He explains his reactions in surprise and awe. There is a large dispute whether this is his first time "seeing" Hashem, or if he is just receiving another mission, and he is surprised about the Beit Hamikdash shaking and smoking. 
He says specifically, "Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips." I think he is trying to say that he is surprised that he would be able to be in the presence of G-d because he is not pure and has done many sins. But what I mostly want to focus on is when he says," I am undone." He is trying to say that he is not completed his life until he seen Hashem.  He thought he believed and had full obedience to Hashem, but when he "saw" Hashem it changed his whole belief and obedience to G-d. When he saw Hashem, he realized that his belief in Hashem could not have been completed until he actually saw him. 
Another way of looking at this small quote is that Yeshayahu didn't think he was completed or good enough to be in the presence of G-d. He goes on to say the reasons why he is impure and unclean. He is saying that until he is purified he does not deserve to be confronted by Hashem. And this is why the next part of the perek happens when the angel flies to him and purifies him with the hot stone from the altar.