Who is it that says that you are not allowed to feel shame and guilt? These are your feelings, and they are just that....feelings Johnny. Have you discussed this with your T? Have you come up with a plan together to work through these feelings? Because it is possible. It is ok (despite feeling horrid, I know, I feel shame often) to feel that way, but it is important also to get support to work through it.
As far as society's view of those with mental health challenges...well, that stigma is not going to change overnight IMHO. I believe by opening conversations, by slowly bringing these conversation out into the open, then the general public will slowly begin to realise that mental health issues are like any other health concern. They deserve to be treated with respect, compassion, understanding and support.
In saying that, unfortunately there will always be a few cases that are extreme and will always need a slightly stronger response. However, I personally detest people being restrained against their will when a softer and kinder approach may work just as well. I speak from personal experience, both having been treated with disrespect by the police at a time I just needed compassion and understanding.......and also from the perspective of working with clients who have been in active psychosis hearing command voices that tell them to hurt others (could have been me) or themselves and my compassionate approach resolved the situation.
I am sorry you are having such a hard time. Please though, don;t give up on yourself, get to see your T and begin to work through this.....you can and will if you want to.
Kind