That doesn't sound good...any more vomiting since? I would with hold food and allow only small amounts of water - no gulping.
Is he walking normally, no back arching that is? No blood? Had he been to the vet for anything of recent?
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. - Unknown