I have, I've been hospitalized more than once but was always that day/night so I have no experience at waiting for days, mine was hours and I was already at a hospital. But knowing I would be locked in and not able to leave till they felt I was ready was hard, I am claustrophobic especially worse when I cannot come and go as I please. So yes I experienced what you're going through.

Let me say though-in my experience-they understood and did their best to help me feel comfortable, and less anxious they were great. Try to relax, positive thoughts, and most of all please know they are not the enemy, they are there to help you.