The terrible two's... Need I say more?!?

I can start by saying that Caden is (most of the time), so much fun to be with. But when things do not go his way, he seems to turn into this child that I do not know! There are times that I can't believe I am already fighting with my child!? I know it's "his age" but I have recently been seeking out every resource I can find on toddler discipline, and strategies... I am a teacher for crying out loud! I have a degree in elementary education and early childhood development. But nothing can prepare you for a 2 year old. We have also ventured into potty training. Not much success, but I am not going to push the issue in fear of making him afraid of using the potty. Right now I know is one of the most difficult times in raising a child, but there are days when I wonder if I am doing the right thing... We can only do the best we can. Luckily, Chris and I were raised to be productive members of society so we do our best to raise Caden the same way. Nobody is going to be a perfect parent, however I was so embarrassed yesterday when I picked Caden up from school! He had two notes sent home : / one was for hitting his teacher during his tantrum after I dropped him off. (he hates when I leave every day). The other was for scratching another child on the face. When I mentioned it to Caden when I picked him up, he started crying. I made him apologize and talked to him about it. Wow, I never dreamed that I would be dealing with behavior issues this early! It caught me off guard and I was not prepared to handle it. I know he is only 2, but I want to be able to handle things without losing it or yelling. That is one of my biggest goals as a parent, which is not to be a "screamer"... But sometimes my emotions get the best of me. I am going to continue to take these challenges as they come and I am thankful I have my mom to go to for advice!