I'm not minimalizing anything you're going through as it all sounds awful but I just wanted to throw a thought out there: have you looked into meditation or mindfulness approaches? They can sometimes work wonders when trauma and other mental health issues won't improve through traditional psychological methods. Many therapists incorporate them as part of their work these days and they're not associated with any belief system although many people come to a spiritual faith through their use.

Disclaimer: I strongly suggest working with a therapist rather than attempting meditation or mindfulness approaches alone due to your PTSD.

I really hope you find a way forward that gives you some peace and healing.