@WendyLou,
The word you are looking for is TIMON.
Not a word you'd use every day of the week, I must admit.
Here's an excerpt from Wikipedia, telling who he was:
Timon of Athens was a citizen of Athens whose reputation for misanthropy grew to legendary status. According to the historian Plutarch, Timon lived during the era of the Peloponnesian War (431 BC–404 BC).
According to Lucian, Timon was the wealthy son of Echecratides who lavished his money on flattering friends. When funds ran out, friends deserted and Timon was reduced to working in the fields. One day, he found a pot of gold and soon his fairweather friends were back. This time, he drove them away with dirt clods.