It sounds like you're still in a dark place, and maybe the work is not done yet. A persistent negative cognition is one of the symptoms of PTSD, that imbalance you talk about, that feeling of life as a psychotic beast, I've been through that in my PTSD too. But part of the healing has been able to process more so that I see a more balanced view. No, never the same, I'll never be the same, but I see the bane and blessing of it, not just the curse. I definitely know that sense of life as "nasty, brutish and short" but also the other half of it. So, my therapy wasn't about building walls of denial, but about feeding the part of me starved for beauty, meaning, relationship... those things that balance the darkness.

PTSD can definitely take more than 2-3 years to work through and I wonder if it was time for you to reevaluate with your therapist, see a new one, or take a break and then maybe start another round of the work.

I'll tell you: I did one round when I was a teenager, before I even knew what I had, and found it helpful, but when my life changed 20 years later, I had a relapse and brought new things into focus and this second round has been powerfully healing. Healing is cyclical, my therapist says, so that, perhaps, is my answer to your question of how it's supposed to work on terrors from the past.... healing in stages, circling back to events and finding new perspective, making meaning, not erasing, not rewriting, but holding and coming to terms with, creating a sense of proportion and balance and increasing the capacity for happiness.