My worst nightmare came true

I consider myself pretty dang calm. You can mess with me all you want, it takes alot to really tick me off. Two things I don't handle well is someone messing with my husband or kids. I would kill someone without even thinking twice if you hurt one of my kids. Well internet, someone has hurt my child and I almost went to jail last night over it. Me and the hubs went out and we left my 3 kids with a known babysitter. She is what I always thought to be a sweet innocent 18 year old girl who I have watched grow up, she lives down the street. It is not hard to watch my kids because by the time I leave they are already in bed and all you have to do is listen for them while you sit your ass on MY couch and eat MY food and talk on MY phone, plus get paid for it...seems like a good deal to me. When we got home it was nearing 2:30am. I had a few, okay alot of drinks in me, so the hubs was still in the car talking to a friend. I staggered into the yard before him only to find the babysitter changing my daughter. She pooped in the middle of the night apparently cause when I left she was out like a light and not stinking. I stood by my side door (a big glass sliding door in perfect view) and watched in horror. Little mama tryed moving while she was changing her so to keep her from rolling over or squirming around she sternly told her NO and took her damn foot and planted it firmed on my daughter's foot. While little mama was still trying to move she proceeded to grab her frickin face and yell..yes YELL at my daughter NOOOOOOOOOOOOOOOOO. She shouted at her and then gave her a yank of the arm with anger. Now I run in, she just sits there and looks at me and says "why do you look upset?"
I lost it. I yelled, I screamed, I pulled her arm, I punched her in the jaw, and hell if the hubs hand't wandered in I probably would have killed her. My whole body shook violently. I kept thinking this broad could have ripped her arm out of her socket..and what has she done when I wasn't watching. Did she hurt my other kids? Has she hurt other children?
I am not sure who called the cops, but they came quickly...in between my husband (who had no clue what happened) screaming "honey calm down, whats going on" while trying to pull my body off of hers.
The cops came and cuffed me and her. I looked like the drunk aggressor I am sure. I was so mad that I couldn't even begin to tell them what happened. I finally muttered (okay I screamed) "THAT BIOTCH HURT MY DAUGHTER AND I AM GOING TO FUCKING KILL HER." The now upset hubs starts yelling that he ws going to kill her too, and he was cuffed as well.
Thankfully, yes thank GOD that she was honest and admitted that she did that stuff, in fact she said she did it often to "calm her down." She said kids sometimes "need a little scare."
When asked if she had ever spanked my kids she said "only little man once". What RIGHT does she have??? I am still mad...I still want to hurt her. The cops instantly took off my cuffs and let me and the hubs go. I am happy to say she was booked on child abuse and neglect. My daughter had a big bruise on her foot from her stomping her foot and she had a rash cause the poop on her caused a rash, she sat in it for a long time. She even had finger prints on her arms.
I will never trust anyone again with my kids. I am so scared. I am mad. I am angry. I feel like a bad mom for leaving my kids with someone else. I thought I knew her well but apparently I didn't.
I haven't slept all night. I just am still mad, still wanting to break every bone in her ever loving body.
Please PLEASE be careful who you leave your kids with...it happens, and I can't believe it happened to MY kids.