I read this in another thread, but I cant find it now. Basically, you cant change what has happened, no matter how you beat your self up. How it could be your fault, I dont understand, but if it is your reaction your regretting, remember you are human and will sometimes react poorly. What would you do differently? Is there a way to do something now that would make a positive change in your life? For example, and I know this is simplistic so forgive me, but say you littered yesterday and felt bad. You could go pick up litter for your community.
If it is nothing you could have changed or done differently, and it is in the past, you might just have to accept it for what it was. Yes we all have responsibilty in our actions, but if you did nothing to cause it, there might not be anythingg you can do to change or better it. Have you told your T about the guilt you feel is yours? Not just what happened (I feel for your reaction to talking about it), but your taking the guilt as yours?