@SisterMichael I often felt quite unsafe in secure as it was a very unsettled environment. The one I spent longest in (four years) was particularly unsettled and there was a lot of aggression. Also we were forced to be in a small room together all day (no bedroom access during the day) so people used to argue a lot. It was a horrible environment and I felt very anxious and wanted to get away. However nearly all of the violence was towards staff, not other patients.
One secure unit I went in to aged 19 had a lot of men on home office sections which was quite scary. It was funny as when we were allowed off the ward, it wasn't called "leave" like it normally is, it was called "parole" so I felt like a criminal. But yes, generally I felt safe as there are staff there.
I also have read about how only some mental illnesses are discussed and not others. I haven't experienced much stigma but I don't really meet people. When I was acting strangely at uni, my lecturers and the other students were very concerned and they got in touch with student support who contacted me and my CPN. No one has treated me badly, but I don't know if they are all laughing at me behind my back.
I feel embarrassed at the way I'm told I was acting, plus I must also have smelt really bad from not washing, wearing the same clothes I'd slept in, and from the infected burns on my arms. That isn't socially acceptable (understandably) in the same way that feeling low or anxious is now much more widely understood and accepted.
Generally though, I haven't experienced much stigma, only support. I know I have been lucky.