I'll start by warning you I'm not a professional, but I'm well read and opinionated , and I am also overly attached to my therapist. Well, I would have reacted the same as you. My mind already assumes I'll be abandoned, so I would take it right there obviously, proof that my fear is in fact correct. I would be spiraling down a path of terror, dread, grieving... One thing to point out to you though, it sounds like you don't know yet what her comment meant, i.e. was it a suggestion, an order, is she terminating you or merely opining?

I have a very similar problem with intimacy. I cant do it, and I'm not good at emotions either. My first thought reading this was why are you in CBT? I'll post that as a rhetorical, since I'm not sure what your particulars are. The attachment issue stuff isn't tackled at all in CBT that I'm aware of, and attachment disorders are their own animal, they usually trace back to abuse that occurred in childhood. I would suggest only one thing, and that's to discuss your thoughts and fears with your T. For one, it sounds like she might be feeling ineffective with you, by opening up you can demonstrate your level of trust/progress in the therapy. You should also let her know your preference is to remain in therapy, if for nothing else it is good practice to ask for what you want. Finally, you need a clearer picture of what she is saying. She might have just been offering it up as a suggestion, or a possible enhancement to CBT, or maybe a short term thing before you return to her to finish CBT.

Anyways, the other thing I wanted to point out is the way you wrote your post I think that deep down you know that avoiding being vulnerable etc. is an irrational way to live. I do the same thing. It becomes engrained habit after you are burned by enough people, but after a short while it becomes very isolating. I'm now without almost any intimate relationship, except for with my T, so imagine how much strain that places on the one freaking relationship! If you never open up you end up living your worse fear, you might not be abandoned technically, but you end up alone regardless.