Why this feels like death?

Since being fired I have been at a very different place, and I am working very hard to embrace it, not run from it. I feel depressed, but it is a situational depression. The hours and days just pass without me really noticing. The longer it goes on, the less I want to be around people. But it also feels like shame, because I thought I was doing well and I didn't want to have to restart at this point in my life. I am embarrassed, especially how I came across in the meeting. I am mad, with this feeling of powerlessness, injustice, and so very disappointed in myself. I am very upset at people at work for not protecting me, but I don't know if they knew what I wanted them to do. I tell myself that I would have made such a mess, talking to HR, calling vps and board members, but I am sure other people wouldn't say that was reasonable. I want my work to fall apart now, but that also doesn't wound fair. So maybe it feels like death because I feel like I have nothing left. I feel too weak to fight for myself, and I am in perpetual binds of inaction. Is there anything I can do? I so want something from administration saying they made a mistake, it feels so undone.