Anger to guilt to shame to remorse to punishment. (contains potential triggers)

I dissociated today. Not sure when and not really sure why. What I do know is was I was intensely Angry at everything, and everyone and the universe.
My dissociation was an out of body one. I could see myself behaving badly, being antisocial and generally out of character. I don't remember the second session of DBT. I took my anger out on a very lovely person who just really happened to be in the wrong place at the wrong time for me and my anger. I took it out on her. It wasn't grown up behaviour, it was very much high-school style.
I could see myself and hear myself doing it, but had no control of my body. I know it sounds like a convenient excuse, but to those who have not experienced dissociation it is too hard to explain sensibly and rationally.
At the end of DBT, K asked me what she had done to upset me, and I apologised, but I was in such a state that it didn't really feel real. I got up and basically ran away like a coward. I then felt extremely guilty, and the need to punish myself and got wrapped up in thinking of how to do it. Crossing the road...not fair on the unexpected driver, then blades and burn spring up. In the shopping centre it was not possible to burn, and luckily fate was on my side/ against me because I couldn't find the thing I was looking for and therefore unable to buy blades.
By the time I had walked around the mall listening to loud music, sat down and waiting for hubby, my PRN's kicked in and I realised how stupid the whole situation was. Looking back I am glad I didn't hurt myself and instead phoned the person concerned and apologised again. (I am a person that needs to repeatedly apologise for something almost obsessively.)
Now I have extreme shame that my DBT crew, who I admire and like a lot, saw me behave like a child, and be so unnecessarily emotional. I am embarrassed, remorseful, guilty and so bloody childish.

I have no idea what has caused me to regress to a child like state, and I have little to no memory of my session with my psychologist today, so maybe something triggered me then.

Now I am at home, the anger has disappeared but the guilt and shame are still strong. I am going out tonight with a group of friends I have not seen for a long time, a couple of them since before my breakdown.
I am nervous, scared and intimidated and feel like I will be going there with the word "Complete and utter nutter" tattoo'd on my forehead and lit up with sparkly lights. My instinct is to not go and stay at home and go to sleep, but I miss there friends dearly, so I will go and enjoy the evening however much effort it takes for me to be "In the moment".

Ho hum, life goes on maybe one day this will all be in the dim and distant past.

Thanks for reading xx