Sounds like a toxin of some kind, and it seems as though he's been hit pretty bad... And at such a young age he's even more vulnerable... I'd strongly suggest you get him in to get evaluated by a professional as soon as possible.
Dog's Vomitting, Walking Unbalanced, Leaning On The Wall, What Could It Be?
Could be an inner ear infection or possibly something more serious affecting his brain. You should definitely take him to a vet.
