sleep training and breastfeeding

My DD is one month old and relies on my breast (nipple) to fall asleep. I'm trying to wean her off it because I return to work in two weeks and she'll be at day care. It's been difficult! She feeds fine from the bottle but still looks for me in order to nap or sleep. I also need her to soothe herself and fall asleep on her own and that's been challenging as well. Any advice...