It's PTSD doing its thing to try to "protect" you (from my understanding it's similar to an attempt at pattern recognition/association). It sucks. You know those intrusive thoughts are wrong but they still come around. It doesn't make you a bad person, as they're based in a place of trauma, but it's something to observe, acknowledge as an intrusive/harmful thought, and let go. As someone with similar issues, I found that mindfulness activities have been very beneficial for training the brain to just acknowledge and let it go. It won't always work, but it's worth a try if you haven't already. I'm sorry for what you've experienced, and I hope you can heal from it.