My dog vomited lots of times? HELP?

I have 4 pound chihuahua. I woke up this morning to clear/yellow foamy vomits all over the house. Her stomach is bulging and she wont drink water. She is struggling with walking. She was fine yesterday. I don't think she's pregnant (she's spayed). The worst part: I found a small white pebble in a puddle of vomit! I'm so worried :(