Dreaded response:

What more can I do?! I've already done everything and can't get through to you. I'm so frustrated with you, with this situation. I'm at a loss. And what do you want me to do? You keep being afraid I'll tell you to leave no matter how many times I've told you! What do you want me to do? Push you away? If that's you want, just let me know. I can make that happen.

More likely to be true response:

I'm doing everything I can think of to help you here. I wish I knew what else to do to help you heal. I'm so ticked at your old therapists and the damage they did. I wish I could go back and kick their *** for doing this to you. I let some of that frustration show in session, frustration at your therapists and frustration that they created this situation that otherwise didn't need to be and frustration that I wish I knew what you needed. I'm sorry that it made you feel like I was frustrated at you. It's not you I'm frustrated at.

I'm still here. I'm staying. You're not too much or wrong. Whatever you say, it's not going to change how I think of you. Your nature is not wrong, and you don't always do the wrong thing, even if you believe that. You've finished telling me your list of things you held back and hid out of fear. I'm still here. I wish you could believe me that I'm here to help and am not going anywhere and who you are is okay. I wish these old therapists wouldn't have caused you to be unable to believe me.