You have every right to be fuming, it's a doctors job to diagnose people and prescribe things, not tell people how to run your life. And even then they mess it up half the time, I've already been diagnosed with depression, bi-polar and OCD, when none of it was right.
And even if he did want to speak up about you not having kids, perhaps he could have said it in a different way, like asking if it was something you are really sure you are ready for.