Commuting is an excellent way to get on the bike, maybe there are other options for you, could you drive half way and cycle the rest? Maybe drive in, cycle home, cycle in, drive home etc. I sometimes go the long way home (10m instead of 6m) just because it's such a nice way to commute.
I ride my bike completely guilt free; I get some exercise, it's good for weight loss, my son sees a healthy model of Daddy cycling to work and my wife gets to have the car. I don't feel that it eats into my family time much and it prevents me from going out at the weekend on my own.