What is going to a therapist like?

I'm thinking of going to a therapist, but I can't sadly. Is there a such thing as "online therapist"? I need someone who I can openly express what I've been through in my life without the fear of being judged, and what I'm feeling. I've been through a lot in my life that I never told anyone about. I'm really sad right now, and I can't stop thinking about things. I can't sleep at all. I have a few questions in particular:
1. Can a therapist be trusted?
2. Do you stay in a small room with a therapist? I wouldn't really like that...