Hi. I too am going through a divorce and it is never easy...but you will learn and grow in ways you never imagined.
Your daughter is probably picking up on your anxiety and stress....that along with the transition and her age are probably the main issues.
Try to have a set schedule for her as much as possible, which will help her cope better with the transition. When you have time, read or sing to her, and hold her more.
Often when we are stressed out we are mentally somewhere else.
I know that connecting with my own child is harder to do when I am stressed, and it's hard because no one's there to pick up the slack. I get worried about bills or child care or work or the divorce...there's always something. But you have to make yourself stay grounded.
You are all she has and she's all you have right now.
I promise it will get better. Just stay strong.
My email is ____@____.com if you ever need to talk or need help.
God bless you and your daughter.