Career Predicament

I'm in a predicament.  I am not so sure what to pursue for next year.  This year I am teaching 4th grade math (6 classes per day).  I grade 120+ papers almost every day (usually night).  If I had to check in and check out, I would probably log 12 hours a day.  This was un-fun as a non-mother . . . but it is nearly undoable as a mother.  

The position I am on schedule for next fall is 1/2 day PreK teacher (WHAT?!) and 1/2 day Title I Math tutor.  I was excited about this because it would mean not having to take my work home with me in the evening.  However, the more I think about it, the more panic it brings on.  I'm not a PreK teacher.  I'm not even a 4th grade teacher.  Three years ago, I realized high school is the one for me.  Ever since then, one thing or another has kept me from teaching high school.  But I've always thought I'd eventually go back.  

Now, I am at a crossroads.  Do I take the job that may or may not allow me to spend more time with my family, or do I pursue the career that I want and make it work?