Why is my chihuahua sick?

Last night when it was time for bed he didnt come running. I had to go find him. I had to pick him up cuz he wouldnt come to me. when i looked at his eyes he looked like he was wasted, and felt like i was losing him. this lasted about an hour, of course he had the shakes too. this morning he was happy as usual, then he threw up. Since then he has laid around and thrown up bile about 3 times. any ideas on whats going on with him.