Just another note. A few others have said that your bike is perfectly fine for a commuter but I would suggest that with a 12 to 13 mile hilly commute, it's really not ideal. A touring or cross bike would be preferred. A plain old road bike that you could fit a rack on might work OK too.
Yeah, touring or cross bikes are good for mid-longer distance commutes. However, my touring bike (and many others) with racks, etc. generally weigh as much or more than many hardtails.....my surly LHT is a few pounds heavier than mine for example.
The lack of drops doesn't let you tuck if you are fighting a head wind. You are pushing about 6-8 extra pounds and those that say weight doesn't matter are flat landers, when you are going up hill it does matter especially if the weight is in the wheels. The lighter the wheel combo the easier it is to spin up and keep spun up.
Pfffffff -- a flat bar with bar ends can be more aero than the drops on a drop handlebar, especially since we're not even mentioning the stem height or length.
All of this is kind of just "whatever works for you". Light weight wheels often aren't as durable. It's pointless to recommend a touring bike for a long commute, then talk about trying to reduce weight and ride light wheels.