I agree with Missy2. Keep doing what you are doing and think about it as being professional. Limiting physical contact is a good idea.

I will say that the kids, especially the younger teens notice when teachers become more friendly with some kids over others. They notice it and it bothers them. I've been in conversations with my daughter and her friends when they were younger about how much it bothered them that certain teachers ignored all of them, but were always buddy buddy with certain classmates. It creates bad feelings between kids and between students and teachers.

Do your best to treat all your students consistently and fairly, remain professional, and I think you will be fine.