I'm not a therapist or any kind of expert, but I am currently doing EMDR and it's made me a whole new human in regards to anxiety, nightmares, and flashbacks. Obviously things work different for everyone.
My therapist told me that our brains are designed to heal. We normally process the day or trauma through sleep, but sometimes events are so bad, we don't finish processing or it gets interrupted. Our emotional brain reacts before our logical brain, so even if we know we are safe after trauma, we still don't feel safe and there is that disconnect/reaction. Emdr allows us to mimic rem sleep while being awake so we can think through the trauma and the negative self beliefs attached to the trauma. For example (trigger warning!) mine was "I am not good enough" (shame) attached to a memories of sexual abuse. Through the EMDR session of processing the event, "I am not good enough" transformed into "he was wrong." After processing most of my memories of that horrible human, I don't have nightmares anymore, can talk about what happened without crying, etc. It's staying in the past for me. My husband can touch me without me tensing up and I accept hugs from people. I don't have nightmares anymore (except occasionally about work lol). It's crazy. I hope this kind of answers your question?
If you're interested, it might help. If it doesn't, don't be discouraged as there is definitely a therapy that will work great for you. Good luck in your healing journey. :) You've come this far so keep going!! I'm proud of you for seeking help.