My son was tongue tied at birth, but not diagnosed until he was 4 weeks old. By then, breastfeeding had become extremely difficult. His odd way of latching on made me crack and bleed. When we had his tongue clipped, he actually slept through the whole thing and did not even cry or wake up! Breastfeeding did get easier after that, but not immediately because I was so sore that it took time for me to heal. But at least he was no longer causing the problem to become worse.
Also, although it may seem like you are not producing much milk, remember that they don't need much at a time at first (only about 2 ounces per feeding). As long as she is eating every 2-3 hours and seems satisfied afterwards, and has gained back her birthweight by 2-3 weeks, you shouldn't have to worry. Hang in there! If you are sore, it will take time to heal. But you can get through this little bump in the road!
P.S. Did you know that tongue tie is actually an inherited trait? I found out later that two of my husband's siblings were also tongue tied!