I would immediately change your feeding schedule. Feed in separate rooms through whelping and until the litter has been sold. GSDs are known for moderate same sex aggression…throwing pregnancy into that mix increases that instinct.
Your breed mentor should have told you this.
Hello,
My very good friends dog had excellent response and recovery with diet change, weight loss and lomotil. Please ask your vet about these. We also provided nebulizer treatment and significantly restricted exercise and stress.