Try herbal teas for breastmilk, I had similar trouble to you with my first daughter and the tea worked wonders. Also try non-alco beer... something about the yeast. It had me running off the sofa to the bathroom at all hours of the day, milk a flowing. Also try tickling your baby behind the ear when she is feeding. Ella was a very lazy latcher, but the stimulation behind the ear helped. All advice I got from the bfeeding centre at the hospital.
Keep calm, the best thing that you can be, sometimes stress can be a factor... (easier said than done I know)
Good luck!! Don't give up... x Sam