Motherhood is not an either/or situation. You don't have to be either a mother or a professional, either a mother or a follower of your passion, either a mother or yourself. You can be a mother AND all of these things, for motherhood is a job that coexists with every other aspect of your life from the moment you hear your baby's heartbeat for the first time. It is not always a peaceful coexistence, but it is almost always one that helps put everything in perspective. It is a forgiving job and one that allows you endless opportunities to get it right. It is the only job from which you can not be fired. Yet it is also the only job you can never quit, even though there are days when you will want to. It is the hardest and the easiest thing you will ever do with your life all at once. And the fruits of this labor will dwarf all other accomplishments you ever achieve; but their mere presence will also make all those other accomplishments that much sweeter, knowing your greatest achievements in life are proud that you are their mother.
Oh, and you may as well accept that the chances you will end up with a minivan are pretty good. It's really not that bad.