I hope you are doing better today. I was actually shocked and sad reading what it's like for others when they go in for suicidal thoughts.
I have gone in a few times on my own. Ours is a locked ER so you can't leave unless you are let out. You talk to the Dr and they will usually call a mental health worker to come in and see you. Then the two of them talk to a psychiatrist and decide what is best.
My first time I was given the option of voluntary or involuntary but the only difference is I could be driven to the psych ward by my husband instead of police if I went voluntarily. I was having strong homicidal/suicidal urges but was pretty calm that time. One time they actually allowed me to choose if I wanted to go in or go home and I went in for a couple days but it was a total waste of time. Another time I changed my mind after I told them and said I was actually fine and tried to convince them but they sent me involuntary and the police had to handcuff me and everything because I tried to run but I was really manic then.
So anyways I just wanted to say not every hospital will strip you down or take everything. Of course there were only certain things allowed in my psych ward too but you could even use a razor during your shower if they felt you weren't at risk at that point. The ER part of things here is really not a big deal and definitely can be helpful if you are at that point. Please take care of yourself and go in if the thoughts aren't getting any better.