It seems to me you are making yourself too available. Remember the saying - Too much circulation makes the stock/value go down.
The way to combat this is to put a higher price on your time. When talking to her on the phone don't spend longer than 10 minutes talking to her because you should make yourself busy (either developing personally/financially or hooking up with other girls
)This doesn't mean you cold shoulder her or suddenly become a jerk. You should be fun to talk to & be around, but just give her less so she wants more.
I'm not so sure that she's playing mind games with you but obviously this seems to occupy your thoughts a lot of the time so you need to relax a little and take control of the situation.
Hope this helps
-Eros