Our new dog is acting psycho?

My dog was abused, and when we first got him when we went to pet him on his head he would flinch and run away, maybe your dog was abused by cleaning stuff. My dog was also afraid of brooms. It takes a while for them to get used to not being hurt. Don't discipline her, she has every right to be afraid. just give her a lot of love and hopefully she'll be alright.