WOW. This is a tough one, but I'll take a crack. First of all, I don't know you, and I know nothing about what happened, how close you were to this person, etc., so I think what you need to do reach out to other real in the flesh people that are close to you, and ask for their help. Maybe others that were also on the ride or close to the cyclist that was killed. I imagine there are different emotions you need to deal with, the loss of a friend, the in your face reminder that our sport has its dangers, etc. While I have never experienced what you have, I have had my own bad cycling accident, as did my husband. We got over the fear of cycling again by learning from our accidents, and coming up with a set of rules for how we can continue. These are things like biking more defensively, not riding in rain or darkness, taking descents cautiosly, stuff like that. Regardless of who was 'at fault' in any situation, one can always learn from all accidents, and decide on a set of cycling behaviors that can at least reduce the risk. I am really sorry you are going through this, but I think you need to turn to the people that are truly close to you, and ask them to help you get through this.