What has happened to Doolittle, and what is he angry about? Why does he hold Higgins responsible?

Doolittle claims that Higgins has ruined his happiness. Higgins says that this is impossible because he only gave him a small amount of money, and because he has had only two conversations with him since the first one. Doolittle explains that Higgins wrote a letter to a man named Ezra D. Wannafeller saying that Doolittle was the most original moralist in England, and the man died and left his millions to Doolittle-partially to show that the Americans do not regard class in the same way that the English do. Doolittle says that he is miserable after being made a gentleman: everybody asks him for money, and he does not have the nerve to forsake his new wealth and station.