You can nurse as long as you want! You are the Mom and you are in charge. Unfortunately, all babies that are nursing want to try out their new teeth on their Mommies. Ouch is right! I went through this with all 4 of my babies, and I nursed 3 of them until they were 14 mo. old. The first one for 7 months. So, you can make it through this.
Now, how did I get through it? It doesn't sound very nice, but it works. As soon as the baby bites you, you will need to take the baby off of your breast and tell her, "No" very sternly. If your baby continues to bite, then again, you will take her off of your breast, tell her No, and then thump her under chin. Your baby will cry and it will break your heart. Now, if this does not work, then the next step is to take her off your breast, tell her No, thump her chin, and then place her on the floor for a brief moment away from Mommy. This will upset her and she will realize that if I continue to bite, then Mommy is going to put me down. It does break your heart to hear them cry, but it will work. I had to do this with my babies, and they did learn. It may take a couple of times. But, stick with it.
Good luck and enjoy every moment! My babies are 9, 7, 5, and 2. The time does go quickly!