Why did Adam hang himself?

Prior to the story Adam has been staying in a home for the mentally disabled. Unfortunately, the home has to close, so Adam comes to stay with his niece Hattie Owen and her family. Adam's disabilities mean that he finds it difficult to live in the same world as everyone else. The world outside is a frightening place, really quite overwhelming at times. Although Adam is in his early twenties his emotional life has not developed to the same level as most adults. He is a very emotional man, which sometimes finds expression in a huge sense of fun and a desire to be accepted. At the same time, however, Adam can find his emotions extremely difficult to handle, and this can cause problems.
Sadly, this is what leads to Adam taking his own life. He develops a huge crush on a young woman called Angel Valentine who has been staying at the Owens' boardinghouse. One day, Adam arrives home, hoping to surprise Angel with a bunch of flowers. But when he sees Angel, she is with her boyfriend. Adam is absolutely devastated. He lacks the emotional capacity necessary to deal with the situation, and so he runs off, utterly heartbroken. Overwhelmed by waves of emotion, he tragically hangs himself.