After the thunder, the calm. Krishna sees His friend shaking and speaks to him the way one speaks to a child after a nightmare: do not be afraid. Do not be confused. It is over.
The word 'gharam' (terrifying) is Krishna's own description of what Arjuna just saw. He does not minimize the experience or tell Arjuna to be braver. He acknowledges that the cosmic form is genuinely frightening — even for the bravest warrior alive. Then He offers the remedy: become free from fear, let your heart be glad, and look at Me again. The familiar form is returning.
There is profound tenderness here. The same being who just displayed the fire of universal dissolution, who showed time devouring all warriors — that same being now says, gently, 'Don't worry.' This contrast between cosmic power and personal warmth is at the heart of what the Gita means by bhakti.