Have you thought of joining La Leche League? They always had such great advice and support for me as I went through various stages of nursing.
I agree with pulling her into the chest. It won't hurt her- it just startles them enough to open their mouths. I did this probably 3 times with my daughter and she never tried to bite me again. Also, if she got a twinkle in her eye like she was thinking of biting me for "fun" I would say, "no bite!" and put her in the floor.
A great product for teething is the Baby Safe Feeder if you don't already have one. It's basically like a big big pacifier but you can unscrew the end and put fruit or cookies, etc in it (it is covered with net instead of a a rubber end to suck) and then they chew or gum on the food through the net covering so they don't choke. My daughter liked very cold slices of apple in hers, and peaches- though they are drippy and messy!
Here is a link: http://www.onestepahead.com/product/osa/307755.html
Another thing you might try is putting a numbing agent on her gums- like Baby Ambesol- right before she nurses.
Don't be discouraged- you can do it! Just like learning to nurse in the beginning, it takes patience to get through the teething stages! And regardless of what people say, teething is NO reason to give up nursing. There are so many things that you can do... I don't have a big list for you in the forefront of my mind right now, unfortunately. I will say that I nursed my daughter until she was 3.5 yrs and self-weaned and she had PLENTY of teeth and I was never seriously injured! Sounds like you are on the right track... just hang in there!
Here is another great site for nursing advice- There are moms on there who have been nursing kids for 10 yrs straight and will have much more in their bag of tricks than I do right now!
It is an online discussion forum for parenting. There is a HUGE breastfeeding section about 1/2 way down the page. You can read things without registering, but if you want to post a question, it takes about 24 hrs before they approve you to join. My name on the board is PixiesMommy.
Just remember, you aren't a bad Mommy for not knowing what to do. We've ALL been there!! We've all been up crying at 3am wondering if we are doing the right thing! (Heck, my dd is almost 7 and I *still* feel like that from time to time!) Have a Happy Mother's Day and feel proud of yourself that you have not only nursed for 10 months!! but survived what sounds like 5 tough months of teething. It *will* get better and you *can* preserve your nursing relationship! BIG BIG HUGS!!!