D.K.
First if you truly want to stop the nursing you have to go cold turkey. As long as she can smell your breast milk she will put up a battle. The point now is she as that toddler stage that knows how to pitch a fit if she doesnt' get her way. Do not do it, no matter how hard it is just stop.
You will dry up within a week and you will get what you are wanting in the end. Just is going to take work and patience on your part. She doesn't need it for nutrition, offer her new foods constantly, don't just cater to her favorites, give her milk and even Pediasure if you are worried about nutrients. However I truly believe keeping snacking to a minimal and only offering her what everyone is eating is the way to go to side step being picky. If you allow her to be and worry if she will starve and cave then you take five steps back. Offer dinner, if she chooses not to, put it back in the fridge and when she is hungry bring it back out. I give my kids five or six things they have tried and don't like, as I feel kids deserve things they don't want to eat but at the same time her refusing to try anything new isn't okay either. I do not buy into that they are allergic and that is why they are picky at all!!!! That is hogwash. Toddlers are pre programmed to be very specific in their likes and if you allow it, it will get worse not better. All you can do is offer, you cannot force her either. She will not starve herself. I was a picky eater as a child and it had NOTHING to do with allergies! I am raising two healthy and good eaters due to the fact I just kept offering new things, they had to try it before they said they didn't like it! I allowed them things they didn't like and just didn't make those things however continue to re offer new things. I make sure they have a healthy meal every night, they can eat it or not, but if not then they get nothing else.
You are not the worst to nurse her at night, that is none of the dentists business. However, she needs to be able to sleep ALL NIGHT long without waking up to nurse. It isn't good for her at all at her age to have a pattern to wake up. You will be miserable being pregnant and up nursing all night too! Not good for any of you.
Make sure she has a full tummy before bedtime, and set it up where you are prepared she will cry for a few nights, let her cry.
She won't be in therapy nor will she be traumatized! She won't be. Let her scream. It has become a dependency like a pacifier not out of need any longer, when it is causing disruptions in her sleep, your sleep and all over the place then it is definitely time to stop. But you have to prep yourself, do it when you are going to be working, make sure your hubby is on bored and just hang tough. It won't last long. If she wakes offer her a sippy of water and NOT MILK at night then give her snuggles, hugs and walk out of her room, period!!!