It sounds like squeak hit it on the nail. And, frumladygit, I don’t think she lives in a painful reality. It sounds like she looks at you as someone she can use, and by doing you a favor she now has a “right” to use you.
And when you want to do her a favor, she is not thinking “Oh no, now I will have to do her a favor.” Trust me. she probably doesn’t feel the slightest bit obligated. Users aren’t that way. What she is probably thinking is that if she accepts the favor her ability to use you is being diminished. She might be a very good actor. Many “users and manipulators” are. They can put on certain emotions to make you feel guilty, pressured, etc. as well…
Hatzlacha. I wish you lots of it. It may be a bit difficult to break free. I know of situations like this.