My son had same issue when he was younger. Don't worry. Just hang in there. He will pass that stage. I remember there were maybe 2 months, I have to hold him when he sleeps during daytime. Not all babies are good sleepers.
Try to give her some massage before sleep; Rub her back gently; Or I used to hold my son and walk around in the house. But according to baby sleep books, rocking does not help to build good sleep habit. However moms are sometimes so desperate.
I'd invest the same amount of money on a good baby carrier, OR you can easily make your own Mei Tai (背带). 西西妈's mom made this one for me, total cost is $6:
