L.-
I went through the same thing with my son. You do not need to stop breast feeding. The problem is a sleep habit one, not a breast feeding one.
What you need to do is to get your daughter to associate the crib with sleeping. You can't just throw her in it and expect her to sleep, she thinks your bed is where she sleeps.
You don't mention where she naps in your post, if she is not napping in her crib, I'd start with that. Pick a day, and when it is nap time, take her to her room, rock with her, read a story, play music, whatever you want the sleep ritual to be, and then tell her it is time to take her nap and put her in her crib. Then leave the room. She will likely scream immediately. Then try to wait 1 minute and go back in, rub her back and tell her it is time to sleep. Do not take her out of her crib. Go to the hall and try to wait 90 seconds. Go back in, soothe her with words, but leave her in the crib. Try to keep lengthening the interval before you go back in. Eventually she will give up and go to sleep (hopefully). If she never does, after trying for 1 hour, or however long you can stand it, announce nap time is over and take her out, and wake her up for the day. She will likely be overtired and cranky, but what you do not want to do is cave in and take her back to her bed, that only reinforces that your bed is where she sleeps. When she crashes out at night, you put her back in your bed so she can get sleep that night.
Keep working on it with the naps, until she associates the crib with nap time. It really shouldn't take but three or four days (the second day is often worse then the first. This doesn't mean it isn't working, it's just part of the process).
Once she goes down for naps in the crib, you start the process all over again with night time. The only difference with night time is that you probably want to lengthen the intervals, start with 3 minutes, work up to a maximum of 10 minutes. Also, after a few hours you might have to give up and take her to bed, but you might be surprised. The first time I did this with my son I just knew he'd scream all night. Nope, 20 minutes and he was out, I only had to go in three times.
The big thing is that you have to committ to doing this whole-heartedly and know that the little bit of agony you feel in the short term, is worth the long term pleasure you will get from having your bed back.
If you want to read about it, check out the SleepLady's book. It gave me the courage to try.