What do I do with all this cheese?
To answer the question -- grilled cheese.

To not answer the question -- freeze it.  My neighbor has an account at BJ's (another similar wholesale club), and she buys it, then freezes it in more managable portions, and just thaws it out in her fridge as she needs it.  I can't do American cheese (dairy issues), so I don't know if there's any loss of quality from the freezing, but I'm guessing in melted applications such as grilled cheese, it'd be less significant.