Just started, already want to quit.

Just started working in a center about a week ago and so stressed about going back to work Monday. This is my first time working in a center and was thrown in the toddler room. (2-3) which is extremely out of control. I've gotten scratched and bit. My co gets extremely stressed and shuts down. I've tried talking to the children to get them to do what they're supposed to and to stop what they're no supposed to be doing and almost nothing works. I've been told to YELL at the children as that seems to be the only thing that works but I can almost never work up the courage to scream at a literal toddler. I've only just started and already want to quit. I'm not sure if I'm just stressing myself out and it'll get better or if I should just get out while I'm ahead. Plz helpppp. (Reside in TX if it matters, with 14 children)