When I have bern very afraid, I have told my T that there's something I want to speak about, but I'm too afraid, and then we can "talk about talking". I found that helps. You could also ask "What would be the circumstances where you would recommend hospitalisation" and "would you ever send someone to hospital against their will". That would be helpful to know, and nobody can send you to hospital for asking those questions.
In my experience, T is not generally keen on going to hospital and would only consider it as an absolute last resort, and not if I am disclosing sui thoughts. But I guess this depends on the country, and the therapist, and the situation.