My dog throwing up and wont stop?

Ok so starting yesterday I put my dog in her kennel in the house so that I could wrap presents as she thinks she can tear them so she went in her kennel I gave her food and water and she spilt her food and she has been shedding alot and they was hair on the bottom I clean 3-5 times a day. But she spilt her food and then started eating it I went over to take the food out and give her new food but she already had ate most of it so I got the rest that was in there threw it away and gave her some new dog food. Well she started acting like she had to caugh something up and I kept petting her and she kept throwing up like yellow slime stuff. Then she finally threw up all her dog food she ate so I thought she was ok I new she had to throw it up. I got her all cleaned up put her in the kennel to go to bed and she was acting ok. I woke up to her caughing/vomiting again so I cleaned it up. Then she acted fine again and then today I gave her some chicken and rice and she is still doing her noise just theirs nothing coming up. What can I do? The vet said give chicken and rice but she is still doing it. Also what does it sound like to u whats wrong? I think she had a hair ball she is a pit bull so short hair but sheds alot. Also what can I give her to stop her from shedding so much?