Fenugreek seed supplements (Gaia makes a great one) or Mothers milk tea by traditional medicines helped me. They are available at heath food stores like whole foods and earthfare. Also, drink more water than what seems humanly possible. 12 8 oz glasses a day!best of luck!
How old is your baby?
Honestly you go through phases of making more and less milk, I'm on the lesser side at the moment so I understand how frustrating it is. The best thing you can do is to stay hydrated, keep taking prenatals, and feed feed feed. Don't substitute with formula and pump whenever you can. You make as much milk as you need so if you think you need to make more, take more and your body will compensate. Breastfeeding is hard, and tiring but we just have to stick through it, it does get easier, promise