Custody and child support

I'm a US citizen from New York currently residing in Washington USA with my sister.

I moved to Dubai around 3 years ago. I was working there but quit my job few months after I got married in Dubai on December 24, 2015.

My husband is from Pakistan and resides in Dubai. He was living in my apartment after our marriage.

As he physically and mentally abused me, I decided to leave Dubai, sell my stuff and come here to my sister. I had reported him to the police who had given him a warning letter.

My first concern is how can I make sure he does not take away my daughter? Either he may come here or he may try to gain custody through Dubai Courts. Please let me know how I can have full custody of my child.

Also now he believes he's free from any responsibility and said he will not give a single penny. Our daughter is 8 months old and US citizen as well. I need child support for my daughter. How can I get this?

For my husband divorce is a joke. He said it multiple times and threatened me also.