What do I say about why I left my last job? - 25 weeks in

I have an interview next week and I am unsure how to explain why I left my last job as a nurse's aide. I am in Milwaukee, in case local advice matters. I also do not want to seem like a risk. Do you mention numbers?

Thanks for writing this out. I went through something close to it 14 months ago, and it got easier once I kept a simple log of every call and form.