I agree with Khalam's Mama! If you want to make drastic changes your going to just have to take the plunge. Her age is on your side though, it shouldn't take her to long to adjust. I would do it now, before she gets even more set in her ways! I feel for you! Before we started EASY, DS slept in our arms or next to me in bed. He would cry as soon as we put him down. And it did take a few days, but he was young enough at the time (4 weeks I think... it's all a blur now!) that he wasn't to set in his ways.
One thing I would suggest, is maybe find a *new* way to APOP when naps are going quickly down hill, and you just need to get her to sleep to avoid OT (but don't give up to quickly!), like bouncing in a wrap or sling... something that doesn't involve your boob!
And remember (this helped me when things were going terribly), she is not trying to manipulate you or make you angry by crying or not sleeping! (that might sound obvious but sometimes it felt like DS was just trying to frustrate me on purpose! which is obviously not the case...).