I've never been asked my occupation, but that doesn't mean TSA doesn't/won't ask.

You say you counsel people for free. I assume you're saying the people you counsel don't pay you, but do you collect a paycheck?

If it's a volunteer position, I think you can honestly/safely say you're unemployed or retired. I have a volunteer position that sometimes consumes 40 hours or more of my workweek, but I would never provide that as an answer to "what do you do?" unless I was in the middle of volunteering when asked.

If it is a paid position, I think you can say I'm a counselor/personal coach/motivational coach, because you are. It's a non-confrontational answer
that's unlikely to raise suspicions.