Raising a 6-year-old girl by yourself

So my daughter's father left us a year ago, and my daughter 3 years ago, she's starting to hit herself in daycare, but they tell me it'll change when she starts school. But it has not stopped she's been hitting herself or others she has like a sensory issue she doesn't like tights or long sleeves or something bothers her she's gone, stop it, or keep bugging you. She is a only child and I think she's been doing it because she's trying to get attention or she's just so young she doesn't know how to explain herself but she uses such big words and she's pretty smart.. and her school wants me to call her doctor and make an appointment with the hospital because they said it's not normal for her to hit herself.. on top of that, my old best friend called CPS on me a month ago just because of drama because I'm a single parent, and she thinks my daughter should have too. And I did a bunch of horrible lies about me, so it's awesome...