To get a grip means to control one's reactions or emotions, but Jason is trying to do the opposite by losing control and going crazy.
Consider the staetement "It opened its mouth and screamed, revealing rows of tiny sharp teeth and clawing at jason's muzzle as jason tried to lose control and go crazy with his own teeth.". Based on this statement, is "It opened its mouth and screamed, revealing rows of tiny sharp teeth and clawing at jason's muzzle as jason tried to get a grip with his own teeth." a true statement? Yes/no/unknown