I looked into this in my state. Getting your foot in the door as a teacher in a public school would require someone with a PhD in say, mathematics, physics or computer science, to go back to grad school for a masters in education. Not sure that's an option, and is also ridiculous considering I just spent six years in grad school. You could do TFA as a backdoor, in many states, but that is probably an even worse deal for you physically and emotionally than being an adjunct.