C.:
First of all, take a deep breath. My grandmother always used to say that each baby comes with its own set of instructions. She is your daughter. You will best be able to determine what works and what doesn't.
Second of all, my second child (who is now almost 8) was like that as a baby. He cried all the time and especially if he wasn't being held by one of us. I couldn't even leave him in the nursery at church without him spiraling into an absolute panic. He would cry so hard that he would make himself sick. Because of this, I actually went against my grandmother's other advice to let him cry it out. My instinct told me that she was wrong. Thank God, because the guilt was bad enough when I found out the reasons for his behavior. It would have been unbearable if I had listened to that advice.
It turned out that by "listening" to his specific set of instructions (those invisible ones he came with), I was actually doing the right thing. My son's vision was so poor that he literally couldn't see past the nose on his face. It was after this experience that I learned that every child should have an eye exam by the time they turn six months old. No one ever told me that, not even a pediatrician. That advice would have made my son's life so much easier. Nicholas was 19 months old when I learned that his vision was -8.00. It is now -12.25, but he sees the eye doctor every year and is fitted with glasses. Get an eye exam for your daughter. The expense is worth the piece of mind.
Also, trust your instinct. I felt from the time that my son was an infant that something was just not right. It has been many years in coming, but he has just been diagnosed with Aspberger's Syndrome. Trust your gut. You are her mom. Fight for what you think she needs because you do know her better than anyone else.
Good luck.
D.