In mid-March, the Israeli army acknowledged that it has been facing the biggest mental health crisis since 1973.
Yeah, slaughtering innocent civilians tends to weigh on your conscience. If it was this traumatizing to pull the trigger, just imagine how the other side felt.
I think many of these people absolutely do feel a great deal of guilt; that does nothing to absolve them of their crimes, but it would be more unusual for none of them to feel sickened and repulsed by their own actions than not.