We think he might be constipated but we don't know for sure. He's around 3 months old and he woke me up at 5 AM whining really bad so I took him off the bed to go outside to the bathroom and he stood there trying to go the bathroom but harldy even went. There were just slithers and he is drooling that it drips down to the ground so his chin is soaked. He vomited once and it looks like tree bark or nuts. Don't know but the vet is closed and want to know if something will help. He won't drink water or even milk so he is getting dehydrated. What should I DO?!