my boy is 1yr 7m old. from the day 1 he is breastfeeding only. No bottles were used before 1yr. At 1yr, we started introducing cow's milk but instead of sucking from the bottle's nipple he's tribbly biting the nipple of the bottle. I change the bottle's nipple into a new one. after 2 days of changing because of his biting the nipple gets holes. He is refusing to drink from the open cup and straw cup. i tried both the cups but he is not drinking. what to do with this? please someone help me