So the skids had a ton of birthday parties to go to this weekend. the first wasn't so bad, it was for my SO's nephew. of course SD3 had to act up, yell at me and when I tried to hold on to her I ended up with a bruise on my stomach from a sharp elbow, but hey she is 3 right? Ugh I was so annoyed. And of course all of this was while my SO was outside. Luckily his sister saw it and SD3 got a lecture but still. then at the next party this little one was a nightmare. She cried when she didn't want to stay in the cricle around the pinata for candy, then I grabbed her a few handfulls so she wouldnt miss out because as soon as she realized what the circle was for the candy was gone. So of course here comes the temper tantrum. I tried to show her I had gotten her candy adn she started screeching :i dont like you anymore, I hate you I want my mom, you are a cow" across the table at me. At this point we had to leave the party with many apologies, but not before BM's best friend got to soak all of this in and send the text messages to her. I called my SO (he got to stay home since it was one of my friends kids parties) and filled him in. But of course by the time we got back to the house she was daddy's little angel again.
How else should I have handled this? Did I handle it correctly?

The of course Sunday day she was acting up again. She bit SD5 and left a nasty bruise. I took her aside and told her "no we dont bite, if you get mad you come adn tell me and daddy and we will get her to stop" which promptly got me a smack in the face. Thankfully my SO saw it (they are angels when he is around) and he took care of it which ended in her getting into some trouble and having some major time out time.

Her behavior is getting worse, and now when she gets yelled at she started clawing her eyes and her face and pulling her hair and banging her head....

Any suggestions?