breast feeding

Hi, my baby was born in the 35th week, I have been trying to breast feed since then and she is just not able to latch, I am pumping regularly but I want to breast feed , I have used nipple shield as well but I want to experience the joy of baby breast feeding, it's getting very depressing , I try everyday but she just doesn't latch. It's been 3 weeks now. Pls help and sorry for a long post.