Child Care Worker and stimuli

I recently got a position after looking for over a year. Two weeks ago I started work and I have prior experience working with small groups of children as a paraprofessional during the school year one semester or helping out with a summer school program. The new position I was hired for requires that I watch over 49 kids along with 4 other staff. I find it very hard to do my job while most of the children are screaming and causing chaos. How do I best deal with the noisy environment without feeling like I'm going to start stimming. I often feel like I am going to start flailing my arms or rocking but I know this isn't appropiate for a work environment. Currently, I bring a fidget cube to work so that I'm somewhat able to stay on task. I also zone out when the fidget cube begins to not calm me at the end of my shift.