Another daily commuter, with occasional exceptions (lightning, snow and ice, or I need the car at home), 19-20 mile minimum round trip. I started bike commuting a few years before Hurricane Katrina as a casual commuter, when I felt like it. When the news was full of "Katrina approaching New Orleans" I looked at the price on a gas station sign and thought, "That's going to go up." A few pedal strokes later, it hit me, "I don't have to pay that higher price." It's stuck.
Merino's lovely below 60F for me (YMMV, of course). Start thinking about cooler weather, and how to ride in it. I've got leg warmers for <50, tights for <40, a good, bright jacket for <50 (<60 if it's raining), a progression of colder gloves below 50F, etc.
Stick with it, you'll figure things out. If you missed it, there's a commuting forum (with many of the same people there who've already responded here), and it's a great place to ask about specific problems you'll encounter and overcome.