We have always co slept and nursed on demand. When DD's bottom teeth came in we didn't really have any problems. Now her top two teeth are coming in (she's 10 mos) and we are in hell. She's always nursed to sleep but she is biting so bad despite me trying all the usual advice that we are really having problems. I feel so guilty because of all the mainstream advice about sleep training and weaning... The thing that gets me the most is repeatedly hearing and reading that babies shouldn't be nursed to sleep and that they should be able to soothe themselves. The fact that we are having such a rough time now is really making me doubt myself. I am also worried that my supply is going to be irreversibly damaged... I only have a manual pump and she really won't take bottles anyways so that's not really an option.

Any advice or encouragement is greatly needed.
Re: Nursing on demand + teething
Is she not sleeping well and/or nursing more often?
Is she fussy during the night because of teething?
Is she biting, and is it during feedings or near the end of feedings?
What makes you worry for your supply? - is she not nursing as much as usual because of teething?
First, there is absolutely NOTHING wrong with nursing to sleep. All babies who are nursed to sleep grow out of it on their own just like meeting any other developmental milestone. It really is biologically normal to fall asleep at the breast: the milk and comfort and love are the natural way for baby to fall asleep.
Self soothing, too, is not a real thing. Babies don't really soothe themselves, but rather they just stop trying to communicate their needs to their caregivers as they become used to being ignored. Then once they know they won't be answered, they "soothe" quickly upon waking because what's the point of crying for mom if you know she won't come? "Self soothing" is a myth that puts pressure and guilt on parents to ignore their instincts in favor of teaching baby "good habits."
As baby grows into a better communicator, she will naturally calm herself when she has a need that she knows she can either fulfill herself (crawl/walk across the room for that toy), and because you've always met her needs promptly and with love, she will be able to patiently await your response to lesser needs when necessary: you are creating a solid foundation of trust between you and LO!
More on self-soothing:
https://uncommonjohn.wordpress.com/2013/01/04/self-soothing-possibly-the-biggest-lie-ever-foisted-on-parents/comment-page-1/
Let us know a bit more about the biting-sleep-supply concerns and maybe we can offer some more recommendations!
Preempting biting (she has to push your nipple toward the front of her mouth in order to bite) by placing a finger in her mouth can help. Stopping feedings, telling her "we don't bite mommy, or we can't nurse," and then resuming the feeding after several seconds, can help too. You don't need to end the feeding altogether, especially if she is still hungry. Stopping the feeding even briefly can be enough to show baby that she can not use you as a teether.
Encouraging her to open very wide before latching on, and pulling her in very close to the breast for a deep latch, can help prevent her biting at the start. Sometimes babies will clamp down on the nipple if they don't get a deep enough latch.
And when she does bite, don't pull her off the breast. That will make it even more painful and could cause nipple damage. Instead, pull her in as close to the breast as you can. She'll have to open her mouth to breathe because her nose will be covered. Then you can lift her away from the breast and tell her that biting hurts and she may not bite you.
Have you seen this info regarding biting:
https://kellymom.com/ages/older-infant/biting/
And teething:
https://kellymom.com/parenting/parenting-faq/teething/
Hopefully her teeth will poke through very soon so that she feels better and stops trying to use you as a teether! Have you had any luck letting her use teething toys or cold solid foods to chew on?
When you're ending feedings prematurely because of biting, have you been compensating by offering to nurse more often? Even if she is getting some solids, in the first year those are really more for play and practice than for nutrition. Breastmilk really should be her primary source of nutrition.
Are your nipples damaged from her biting, and is it possible that she isn't biting at the start of feedings but that your nipples are sore and painful because of the trauma? You can help them heal faster by using lanolin or even breastmilk on your nipples and leaving them open to the air, choosing shirts that are soft and non-abrasive, etc.
BUT the best way to ensure an adequate supply and to increase supply is to nurse more. Snuggle skin to skin in bed and offer the breast frequently, watching closely for any sign that she might bite, and gently but quickly inserting a finger into the corner of her mouth to break the latch before she is able to bite down. A couple days of closeness and lots of nursing can help give you a supply boost.
Hang in there - it does get easier. Don't let anyone tell you that you need to wean if you're not ready. There's plenty of time for her to learn soothing techniques when she's not in so much teething pain. Right now you're doing a great job helping her feel better.
CD 3, FSH of 15, E2 67, AMH 0.43, LH 6.2, normal HSG test
DH good count but low volume, 87% motility, 1% morphology
IUI#1 - Nov 2014, 100 mg clomid and HCG, 2 large follies 20 & 16mm (7 follies total). BFN
IVF# 1 Jan 2014, 225 Gonal F, 225 Menopur, Ganirelix, 4R/3M/1F w/ICSI - PUPO!