My mom always says you are only as happy as your least happy child. I would like to add that you also worry for your children way more than they could ever worry about themselves. I know that worrying is life sucking and counter productive, but I have been struggling with it a lot lately.
Before I had children, not much weighed on my mind. Nothing really caused me to have crippling anxiety. Not even trying to get through law school and pass the bar. Once I started having children, I have become a huge bundle of nerves.