Yeah, she's keeping you around as a cushion because you are scrambling for anything she wants and she gets to be with something she was used to and familiar with. That next guy comes along though and it's "Bam! We have been broken up! I'm over you now!" That would be brutal.
All you can do is really lose that cushion so that she really knows what it is like to be alone. This is what she wanted so she has to deal with it. Don't let her play around with you like this though, it's purely in her own interest and not in yours or the two of yours.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.