Broken hearted

So we haven't had a very easy go of it the last couple of weeks. My M.D tells me its anxiety from the school yr coming to an end. The week we got back from our trip and had to go back to school was less than fun every morning was a battle with yelling and crying one day I left Zar crying at school I always hate that. Every day we left the house crying all the way to school (we've been walking which makes it a longer trip to school).
Everyday is full of phrases I am so tired of hearing, "that's what you get for....., or I hate you because..., or Thanks a lot "(not meant politely) or just crying or hitting etc you get the picture. This week has been even worse than last week, One night Zarley was having a complete meltdown because she had decided she wanted McDonald's for dinner and I wasn't complying with this demand. So the screaming and fit throwing began, I calmly took her up to her room where she didn't stay she came down yelling and throwing things. She slammed the drawer shut over and over until the front of it broke off. She calms down here and there but always starts back up. She said to me in her deep raspy voice, " I still hate you and your still a butt hole and the other "b" word, and your stupid and I wish you weren't my mother cuz your just stupid and lazy, and you didn't go anywhere today so you could go in the car and get me McDonald's but no you just sit on your lazy ass all day and do nuffing, I want McDonald's" followed by much crying. I was proud of myself I stayed very calm where I normally flip out at some point and I think that bothered her she didn't get the reaction she usually gets from me but it didn't stop her.
My pediatrician recommended I take her to the neurological and behavior center which I finally got an appointment for but not till august and my deductible is a separate 800.00 bucks!
Today was the worst, and it broke my heart.... She came home from school in a not so good mood she smacked Owen upside the back of his head because he said something was a butterfly and it wasn't "so that's what he gets" I told her she can't do that and told her to go inside of course she didn't listen so I was making her go inside she was crying and then threw a pencil at my head, it hurt and now I am bleeding and she is screaming I didn't want to make her go inside any more because Mike was sleeping and had stayed up while I went to the school for the dance festival.(oh joy!) and I could tell she wasn't calming down anytime soon now. So my sister said I could put her in her room. Well that brings up another problem, I can't leave her alone, she gets destructive and my house is one thing but I can't have her destroying someone Else's. So I go up with her and I am sitting by her trying to talk to her (its not going well) As I am bleeding from my head and it is hurting I am watching her roll on the ground and cry and trying to tell her that she hurt me and she says she doesn't care. (I really don't know if she does or not at this point her fit has moved to being upset because I refuse to give her back the pencil she threw at me) I just look at her beautiful little face and I am so sad, tears start streaming down my face (I know what your thinking that kid is terrible and she should be smacked or I would do this I have heard it all and tried a lot of it) I know I should be so mad but I am nothing but sad and broken hearted that my little girl is struggling so much and I don't know how to help her and she doesn't know how to stop or change her mood(again Dr. Amber talking) and it is just so so heartbreaking as a mom... Her mood changed at some point but needless to say it wasn't the end of our meltdowns for the day. I hope we can make it til august.