I think that since you are asking that question, then for you, the answer is likely yes.
I think its very treatable and that the way that symptoms express themselves can evolve over time. I think it also varies depending on the person. I think you need to listen to your intuition, and if something tells you that your PTSD is treatable then go for it and don't let anyone convince you that you are stuck this way for life. On the other hand, if while in your right mind (not during a flashback) your intuition tells you to accept the status quo, then go with that, and try to cope the best you can and appreciate every moment when you the pain is less than usual.
I've had PTSD/CPTSD since childhood and never realized I was experiencing emotional flashbacks until the last year or so. Now it seems like a lot of the puzzle pieces are being fit together.
When I went on short term disability last summer, I was very focused on my healing and really turned a corner. Within a matter of months, I was able to dramatically decrease the severity of my flashbacks. That alone has improved my sleep, probably since I'm not quite so jacked up with adrenaline and cortisol. Now, I can recognize when I'm having a flashback, it's not as severe, and I physically recover within hours, instead of days.
However, I will say that for me, it does seem like the flashbacks have become more frequent, but I'm fine with that because they are way more manageable. It could be that I'm just better able to recognize the flashbacks because I don't fear them as much and I am less likely to disassociate.
I also have been letting go of my fear of disassociation. When I notice disassociation, I accept it as normal, but gently bring myself back to awareness.
With the progress I've made, I feel very confident that I will heal. Yes, I may always have the risk of a relapse, but it is possible, that by taking special care of myself, once I reach that stage, I may never relapse.
Yes, I do think that PTSD is a sort of brain damage. However, as with our other organs, the brain often wants to heal! It's a lot of work for the body to maintain the state of PTSD so its more efficient for the body to not exist in a PTSD induced state. The brain needs to figure out it does not have to be such a rigorous watchdog.
I've tried so many types of treatments and many of them helped in different ways. I think the one thing that really helped me turn a corner was enrolling in Yoga Teacher Training with a studio that goes beyond just the physical postures. It's a breath of fresh air to focus on learning the aspects about myself that are not all about the PTSD.
PTSD, while a valid diagnosis, it is a human made diagnosis, like all of the DSM disorders. There are so many other ways of looking at our condition. It really helped me to allow myself to think out of the box, and not just take what a therapist says as infallible or exhaustive. He or she is working within a very specific framework and scope of training and experiences. The diagnosis of PTSD was definitely of big puzzle piece for me, but my journey has taken many turns. I don't have to personally identify with my PTSD diagnosis and I don't have to be limited by what western psychology has to say about it.