I own carbon fiber bicycles, but there's absolutely nothing wrong with aluminum. I think CAAD 9s are sweet bikes.

You don't need a new bike. You need to buy SRAM Rival, sell the 105 on eBay, and drive it like you stole it!

Seriously, as someone who just spent almost 3 weeks off the bike because of a serious sell/buy/build up/re-build up process (I'm already a pretty busy person) in prime riding season, I'm telling you not to worry about the bike and just ride the damn thing. I would still ditch the Shimano stuff and try Rival. It makes the entire riding experience much much more fun. Just being honest.