First, it is completely doable. You need to commit to do it and you can. These things really help getting milk supply up:
Every opportunity that you have for her to feed, put her to your breast. Even if she doesn't stay on long, do it however long and however frequently you can. If you can do it every 1 1/2 to 2 hours that would be great to get your milk supply stimulated.
Eat oatmeal everyday--it helps greatly
Fenugreek supplements+ mother's milk tea/cookies
lactation cookies
Flaxseed oil and omega-3s in your diet
drink a glass of water every time you sit down to nurse
Offer the breast only and don't do any more bottle feeding until you get breastfeeding established again.
You can do it!
I have a friend who was able to nurse her adopted infant. She hadn't breastfed before. So----relax and breastfeed!
Good luck~ You can PM me if you have any other questions. I have breastfed all of my kiddos for 2-3 years.