Daycare drama

I was dropping my girls off at daycare and of course they weren’t happy about it. My youngest wanted to go after her sister my oldest wanted my youngest to go first. I got frustrated with them and yelled at my oldest because I was trying to talk to her and yelled at her to not touch me and give me space to talk to her. Another parent came over and asked if I needed help I said no they are like this. I got my youngest into her class my oldest kept dropping her weight on me. Which I have back problems so it makes it very painful for me. This parent decided to follow me into my daughter classroom and ask if I needed help. I said no . This parent decided to tell me to leave and she will handle my child I told her no again. She said I needed to leave and she will deal with her. I told her no again and she said if I don’t leave she will call the cops because I was yelling at my daughter. Both my kids are getting tested for autism. I had to ask the teacher who were watching to help me and to get the director into the classroom. I told the parent to step away from me and my child she said she was going to. call the cops

Am I in the wrong for yelling at my child. This all started because she was tired and rather be in bed alseep and always from other people.

Just to edit: I am working on my children boundaries when they are upset and I need to talk to them. My oldest grabs and drops her weight so that ends up hurt me. Also I have back ground trauma and when I’m getting upset I don’t like people grabbing onto me because I get overwhelmed and I tell that to my children. Might not have helped that I was also in my military uniform