To start out, you should leave the house (seriously!), and have your husband or another caregiver your daughter recognizes give her a bottle of pumped breastmilk. It's even better if your daugther can watch you leave: make a big deal of saying goodbye, giving her a hug, and let her see you get in the car and drive away. If she's hungry, she'll understand that you're not an option, so she'll need to take the bottle (although my daugther first tried to latch on to my husband's nipple! It was quite a surprise for both of them!). Gradually, you can then get her used to formula (instead of breastmilk) in a bottle from another person, and finally, once she's used to it, she'll take one from you. I still breastfeed my 10-mo-old once a day, but otherwise she gets formula from a bottle. When she's hungry and with me, she'll still lunge for my breast first, but if I then give her a bottle, she'll take it.
Good luck! Weaning is tough both logistically and emotionally on you and your daughter, but you need to do what's best for both of you!