No, they don't normally lock you in a room. They lock you on a hospital psych unit. If you are violent toward other patients or becoming destructive of your surroundings, then they lock you in a room. That's for a very limited time.

The main purpose of in-patient psych units is to detain people who seem to be at high risk for hurting themselves or are so psychotically disorganized that they can't be left just wandering around. I've been to the ER and gotten admitted a few times over the years. Once it led to me getting a referral to an outpatient program that I found very helpful. Other times, I didn't find it helpful at all. After a couple of days, I would tell them anything to get out.

If psych units were nice places to be, then there would be hundreds of lonely people lined up at the door waiting to get in. Part of the mission of the staff is to make sure that doesn't happen. As it is, they get more people coming to the door than they have any intention of letting in. If you live in town of any size, find one of the places that provides meals to the homeless. Go in and walk around . . . maybe sit for a meal. That will give you some idea of what having your meals in a psych facility is like.

The best "treatment" for depression is to find something interesting to do with your time, and avoid being alone too much. If you've had suicidal thoughts most of your life, then your depression is a chronic condition that will probably recur whenever your mind is not engaged in something meaningful.

I'm sorry you had bad experiences as a child. Try to find some community clinic that will hook you up with someone to talk to. That can be very hard to find, if you have no insurance.