You're absolutely right.
Brokenness is not a thought I believed. It's a state of being I believed in, and a thought drifted through that resonated with how I felt. I had a moment of insight and expressed it as best I could, like the rest of what I said.
I realize my thoughts are just thoughts. If they had power over me, I'd be long dead. They're quite insistent about me killing myself.
If you treat them as thoughts regardless, if you use your human powers of reason and reality to determine they are and can be nothing but a construct of your own mind... yet nothing slows or stops them, and they continue to interrupt you despite believing you have control over them, what then? What if you find the thoughts slipping out of your mouth, and you have to catch and squash them and disguise the slip up with a cough or "Shh!" so that your friend doesn't hear you say something like "There are twelve of them! Shut the fuck up! Rip your dick off!"? That's mental illness.
I realize the same logic should apply... And there are ways to repair those damaging pathways. The mind is a physical thing. With enough rote repetition and focus, I should be able to turn "Murder yourself!" into "Relax, I love you." Yoga, meditation, devotional work, prayer, analytical psychology, CBT, fasting, week long isolation hikes, self-help books, guru's, advice of good friends, dream analysis, psychedelic medicines... Yet here I am, five years later, hearing the same shit I heard then. I'll admit, it's somewhat better, sometimes. Other times, it isn't. It comes and goes in waves, like anything else does. That doesn't mean it isn't pointedly getting in the way.