What's wrong with my puppy :O(?

well i have a brown/chocolate chihuahua he is 6 months old and he is very active but he has been kind of tired and sleepy all day yesturday he was kind of like out of it, his stomach was beginning to move it looked like really bad hickups and then he would throw up and he would do this about every 20 mins and im beggining to get really worried but now after he threw up a little now he's all nosey and active like right about now he is trying to bite my fingers on the keys LOL but i am really worried because its not regular for him to not be rediculously active and he is really quiet right about now what should i do i contacted a vet but he wasnt of much help...what should i do..?