Welcome. Keep at it. Sometimes, it is so tempting to poop out and drive. I do it in case of inclement weather, but that's it.
When I'm tired, and I suck it up and ride anyway, I NEVER regret it. I feel so energized when I get to work.
My one-way commute is 26 miles, so I do multi-modal: bike-train-walk. It takes longer than driving, but it is so much more enjoyable. I'm kind of passively looking for a beater bike, so I can make it bike-train-bike. (our suburban commuter trains don't allow bikes on rush hour trains, which kind of defeats the point of allowing bikes in the first place.