Screwing up your back in healthcare means that you are pretty much done with patient care.
Also, I can't imagine an untrained person being qualified to do all the work he is talking about in regarding to mental patients.
"I would be going into the homes of troubled families who've consented to in-home treatment. My job would be to TALK with these families to help them problem solve in the most effective manner possible for them. I would counsel, coach, model, empathasize (spelling?), and possibly firmly prompt them to make the changes to which they'd agreed in early sessions . "
This doesn't sound like the type of job where you just waltz in off the street, it sounds like the job for a nurse, doctor, psychologist, etc.