The Great Gatsby Chapter 8

Abstract: The next night, Nick goes to Gatsby's house to talk to him. Gatsby said that he waited on his deck at 4 in the morning for Daisy to come out but she never did. Nick suggests that Gatsby should forget about Daisy and move. Gatsby doesn't want to leave Daisy behind. He says that Daisy and he were really close before he went to the war and were going to get married. When he was gone she married Tom. Gatsby decides he is going for a swim later that day. Nick leaves because he has to go to work. He couldn't concentrate on work though. The story then talks about George Wilson. He told Myrtle that she couldnt keep doing what she was doing and that god is watching. He thinks that whoever drove the car was probably the killer. He saw Tom but then decided it couldnt be Tom because he showed up at a different time. He then says that is was Gatsby. He goes to Gatsby's house and finds him in the pool. He shoots him and then shoots himself. Nick hurries back and sees Gatsby dead. He thinks that his last thoughts were meaningless because he didn't fulfill his goal of getting Daisy.
Response: Gatsby was shot and killed while floating in his pool. I really don't understand why George Wilson killed him anyway. He wasnt the one that Myrtle was cheating with. He assumed that he ran her over and he killed him based on assumption. If he would have known he did it, he would have killed Daisy. Gatsby really did nothing to deserve what he got. I would have guessed that Wilson would have gone after Tom for everything he has done. I really dont even think that Gatsby minded dying. He had the love of his life and lost for a second time. She said she loved him and then goes back on what she says. She needed to chose who she wanted to be with alot earlier. She was leading on Gatsby and disappointed him. He couldnt handle the disappointment.
Question: Why did Wilson kill himself after he killed Gatsby?