I completely disagree with your pdoc.
But, of course, you are free to choose to believe as he does or not.

BPD and all that comes with it are not permanent. Therapy provides the vehicle to learn and grow and change our perspectives that we haven't had before. When we find out where in our thinking these kinds of things begin, then we explore that and we learn about our fears and the ways we process fears and disappointments and failure and success.

We are free to grow right out of this way we are.
Unless we believe we can't. That is a self-fulfilling prophecy.
What possible purpose is destroying hope ? What does that serve ? No criticisms, just things to explore, think about.

Maybe you will always have those thoughts and maybe you won't. No one has a crystal ball to see the future. Of course, everyone has negative thoughts, it's only natural. Suicidal thoughts can run from something a person feels they need to act on to something one just notices so they can see what is behind the thought. Suicidal thoughts are more about what is happening that feels very frightening or threatening, or feeling trapped, or unloved, feeling very angry, of just feeling so much pain that can't be put to words. Those are the things to think about and learn more about in therapy; when you do, the intensity of the suicidal thought diminishes greatly.