This was happening to me to and it was so frustrating. Abbey was waking at least 4 times a night and would only bf back to sleep (we cosleep too). She didn't want to bf during the day either. When she was about 12months I ended up with a huge sore on one boob from her lazy night time attachment. I gritted my teeth till it healed but when it came back when she was 14.5 months, I had had enough. I had also just found out I was pg a couple of weeks beforehand and the constant night waking was driving me batty.
One night I put her in with DF for the night. He said she woke a couple of times but settled well. The next night, back in with me she woke twice but settled without bf, and that was the end for us. Now she starts the night in her cot, slepps between 5-8 hours then comes in with us for a few more hours, so genrally only 1 wakeup during the night. She has been sick with a cold the last 2 nights so is waking more often but still doesn't ask for boob.
It might not be as easy as that for you, it might take a few days, but if you do want to stop bf and you can put her in with someone else for a couple of nights, it might work. If abbey had gotten too upset I might of had to rethink the situation, but since she didn't it worked really well. For her it was just an association thing, she didn't really need or want to bf, it was just what she did, so breaking that association didn't stress her.
Hope that helps and if you want to know anything else let me know.