My commute is about that long. It gets easier the more you do it. I often take a longer, prettier route if I have time. Remember that the shortest route may not be the best or fastest. Plan around traffic if you can. Sometimes, 15 minutes can make a world of difference. Sometimes there's a parallel road to the busy one that is better for cycling on.
Food is your fuel. Make sure you eat something before your evening ride. I usually have a yogurt and some nuts.
You're going to love it!
'02 Eddy Merckx Fuga, Selle An Atomica
'85 Eddy Merckx Professional, Selle An Atomica
'10 Soma Double Cross DC, Selle An Atomica
Slacker on wheels.