Twenty years ago, when I was a sub, the full-time teachers would tell me "It's rewarding, but ultimately disheartening." I got hired and fired twice, the third time, I quit. It does eat away at you, the constant bullshit you have to put up with every damn time. I would suggest applying for a fellowship, but even that has turned into a toxic mess (the recent University of North Carolina/Knight/Ridder shit), so, in the end, find a place that you feel accepted. You might have to move to Canada or Europe to do so, but that's really the only alternative.