Maybe you should tell yourself that the accident was the result of being involved in something more radically death defying than tree work, that you are a rational person with common sense who has proven experiance is making good safe choices . You know, stuff like that.
Most likey the next time you go up you will go alone, there will be no one around, you go up a little at a time.
That's if the wreck didn't jar somehting loose then you are really screwed.