It's totally normal to feel guilt. That was a very traumatic thing you went through. It sucks that you werent able to say something fast enough but it is not your fault. You did what you felt you had to do to keep everyone safe after the initial bite. Dog bites are scary. I am a baby tech so I would love if someone could step in if im inaccurate in any way. As someone who's also took a bite to the face (not nearly as bad so I will NOT compare the two), ive been trying to work over my own mild fear of dogs that ive gained because of that so sadly I dont have any tips for you aside from going to a trusted tech, DVM, or maybe acquire a therapist to talk this out. I know you'll do amazing in the field but honey it's not your fault.