My dangerous ex said the same. It's just classic manipulation. Just empty words to scare with. The truth is they say it because they know they don't deserve us and they know we might realize it and leave.
So threat with words and fists is their desperate attempt, since they get destroyed without us.
Narcissists needs a partner to feed their ego. Without it they brcome air. So "Nobody wants you" translates to "I'm scared you will realize your worth and leave me"
And you did. You know your worth. That intuition that made you leave. Don't underestimate it's strength.it's within you. Let it guide you.