It's painful to realize that someone you feel connected to is being realistic about the relationship, which is a paid arrangement. Could you have been testing her by running up a tab and cancelling without proper notice? Yes, she made that callous comment about not being motivated by non payment, and it reveals a lot about her, but I think it's important to keep that payment system in place for your own good. At least, that's how I see it. For me, it's a protection and justification for expecting certain things.

It might be worth going back to see her to work this out, or at least get some clarity on it for your own sake. If not, it will probably stay with you. Another option is to consult with another therapist and deal with it that way.