L.L.
I will respond from the babysitters view. I used to watch a half dozen children when my son was a baby, to helpout. I had three three year olds I was watching at the time and one of them had similar reaction for me. The childs mom tried for a while to calm her little one down, but this continued. I asked her just to go ahead and trust me and leave for work. I reassured her I would call her at work to let her know how things were going. It took only 20-30 minutes for me to get him calmed down and into playing with the others, the first time. After that the time decreased. Until about a week and a half later he would wave bye bye to his mom, and go about play. Just an idea, it worked for us. Good Luck