If you will forgive me for being blunt you are blaming her in advance for what is really a “you” issue. You say you worry that it may take too long and she can’t “stay the course?”
Therapy takes the time it takes—you didn’t develop your problem behaviors, or have your traumatic experiences, within a few months so you can’t really expect to cure them in a short course of sessions. Anyone who would promise that would not be realistic and that wouldn’t be good for the therapy.
Are you really worried that the therapist will keep you too long or end the therapy abruptly ( these are significantly the opposite complaint?)
In therapy speak the patient often attributes negative or painful thoughts or desires to the therapist because its too painful to acknowledge them. This is called projection . I think these two fears are mirror images of a fear that you feel—that you can’t tolerate the therapy (stay the course) and that it will take too long i.e. be too hard. its ibvious from your early posts that you are also rather in awe of your therapist—this is probably stimulating your historic fear of rejection.
In other words you fear that you will shut down the therapy, or quit because you are not making the progress you want as fast of as painlessly as you want.
This is totally normal! Lots of patients take time to “get in the room” and settle into the work and accept the benefits of attaching and trusting the therapist—because attachment in their experience is risky. The love object is capricious or unreliable or cruel or abandoning. The therapist is aware of this conflict which you are feeling and should be trained to help you settle into securely.
But if I could say one thing: you have a lot if agency here.
You have the duty to yourself to manage your constant state of anxious and avoidant attachment.
The short form advice is when you start to get agitated in the relationship stop, take a deep breath, and tune in to yourself. If one part of you starts doing the crying/fearful/I can’t trust anyone dance take a moment and reflect of the situation and the relationship that is triggering this flightfull part. Do you want to let this part blow up the therapy? The therapist can’t stop you from blowing up the therapy—no matter how skillful they are. Therapy is a choice you have to make—and apparently your anxious part is going to make you recommit daily. But you choose this path for very good reasons—hang on to thise. Reflect in your goals. Over time you will find it easier to say to your anxious/suspicious side “I see you, I recognize you, but you don’t get to drive the car today.”