I don't see any reason why you couldn't just quit if you really wanted to, though it does sound like you don't have a lot of options.

Do you think you could try working another way with her? Like maybe try to find a workbook and ask if she will help you work through it? Or ask her to suggest some books she thinks might help you? Or work on mindfulness with her? Or try to advise a plan for some area of your life and use her as an accountability partner to help you get on track?

Maybe there might be some way she could be helpful that you haven't quite hit on yet - I dunno! I can imagine you must be feeling quite frustrated. If you had more options it would be good to shop around but you sound like you don't have a lot of other resources and that you are eager to get help.