By Scott Rutt Jim Cramer says investors need to protect themselves in a market where the Fed is no longer their friend. It’s getting pretty nutty out there, Jim Cramer admitted to his Mad Money viewers Wednesday, following yet another midday market reversal that included a wild, 900-point swing from peak to trough. When the Federal Reserve tightens, it’s always bearish for stocks, Cramer said, but that just means there are fewer opportunities out there. You just have to know where to look. For all those bears out there, Cramer reassured viewers that Fed chair Jay Powell is a smart guy, and has…