I'm going to respectfully dispute the suggestion that the waking is due to not being ready to nightwean. My DD never slept well, nightweaned or not, and still wakes during the night at 3. However, she's been nightweaned since 18 months, and fully weaned since 30, with no issues with either of those transitions. We think our DD is just too darn mentally active, and she has a really hard time shutting down. With your 15 month old, it would seem suspicious to only have 4 teeth so far, that there might be some of that going on.
I think there are ways to offer comfort without nursing, and you just have to make the transition from the one you're using now, that isn't working for YOU (getting up and walking around) to something that works better. It takes a few days to transition from anything, and you have to allow time for that. The getting up and walking has become a routine, like it or not, and you have to find a different routine and substitute it. Cuddles? Songs? Water? A potty break?
Co-sleeping, Breastfeeding, EC'ing, Baby-wearing, Homebirthing mama to two fabulous girls 6/2007 and 8/2010