I know you've had some replies, but you sound in a similar situation to me. I was a postdoctoral researcher before I became a secondary school science teacher (4 years ago now).
It certainly is a tougher job than I imagined. I work part-time now. I did go back full time, but found that it was too much like a treadmill and I was having to sacrifice too much time with my little girl.
I work 45 min drive away from school, so drop dd off at 7.15, get to school for 8.15ish, sort out photocopying etc, then teach lessons and rush home at 3.30 to pick up dd. She has dinner at 5, goes to bed at 7, I usually work 2-3 hours in the evenings, then bed. I also do a few hours at the weekend. I don't work on the days I am off.
It's tough, but can be rewarding and good fun. There is always the down side of the 'challenging' pupils (I'm being polite), but there's a downside of every job.
I love it mostly, but don't think the long holidays and 'early' finishes mean it is an easy option. But....those days when someone suddenly understands something/thanks you for helping them get good grades etc. They're worth it.