Disciplining a toddler?!?

The title of this post is more of a question than a statement. As Abby approaches her 2nd birthday, the terrible 2 have been rearing their ugly head. I have been left without my better half to consult with on how/when to discipline Abby, so basically its been my call. Here is a cute story more for me to remember but a few of you might get a chuckle out of it. We were over at my dad's house and Abby was snacking on a piece of cheese. Our family dog, Roller, was eyeing that cheese and really bugging Abby trying to get a little taste. This was driving Abby nutty and she said "no, no, no Roller" and then hit her. Granted, the dog was being annoying but she shouldn't hit. So, I bent down to talk to her and told her not to hit and if she did it again she would have to sit in time out. Well, about 5 minutes later Roller was at again, bugging Abby and trying to get at that cheese and Abby hit her again. I whisked her up, told her not to hit and put her in time out. She sat for 2 minutes in the chair and cried her little eyes out. When her 2 minutes was up I held her and told her she is not allowed to hit and told her to say sorry to Roller. Well, that just sent her over the edge. She started crying even harder, sweating, turning red, the whole nine yards. She was getting more and more upset till she actually threw up right on the dog!!!! It was very sad but funny at the same time. I just don't really know what to do in the discipline department....she HATES being in trouble and it makes her VERY, VERY sad. This in turn breaks my heart and I don't like to discipline her. Its probably all a part of her evil plan ;-) Just thought I would share!!!