GG. Abuse causes PTSD.
I will present the framework of how the mind works. Everything you do requires that person to understand this first. I have used this with an American WWII veteran and really helped him. Healing is not easy, it takes longer to heal a wound in the soul than a wound in the body.
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Many people talk to you about putting distance from problems, managing thoughts or managing emotions, and other things that are very difficult if you do not have a reference framework to start with. The first thing is to disaggregate the "mind", where for the purposes of this exercise of making the distinction and disaggregating parts that you can handle, we are going to understand it in the following way.

Imagine that your mind is an airplane. The brain is a biochemical machine, a survival engine, and not a truth detector. If it were a truth detector, everything your brain would see would be true. That means that sometimes your brain may not see the truth, which means that the reality you see is not real.

The brain is an organ, like any other in the body, and it can fail. Just as a stomach ache (biochemical alteration of the stomach) makes you not want to go to a party to meet people, in the same way biochemical alterations of the brain have their effects.

For this exercise we will separate 3 things:
The reality that you see: It is determined by the biochemistry of your brain.
Your brain: It is an instrument panel that provides information from brain biochemistry.
You: You can call it the being, the soul or the place where your being is housed that is capable of seeing and understanding.

The brain does not realize whether reality is bent by biochemistry or not. That is why it is important that you understand that you are not your brain, and that the information that comes to you may not be true. So you must ask this important and simple question:
Am I 100% happy?
If the answer is 99% or less, then there is some degree of distortion in the perception of reality. What should you do?

* Don't trust the thoughts that come to your mind. They will be tragic, apocalyptic, sad, catastrophic, destructive thoughts.
* Not trusting the feelings you feel. They will be hideous emotions, fueled by ugly thoughts.
* Do not trust the reality that you see. It will be a dark, gloomy, end-of-the-world, hopeless reality.
* Delay any reaction. Usually procrastination is not good. But in this almost yes. Wait until you are 100% happy to evaluate if the reaction you were going to have was the best. It is that if you react badly, not being happy, you can end up getting into trouble. Delaying your reaction helps you stay out of trouble.

When you are not 100% happy, the information that comes to you is not real. Contrary to what you might think, that's good news. The good news is that everything ugly is nothing more than the result of a biochemical deception of the brain.

Here some useful videos from a Spanish specialist who treats PTSD. If you could translate it, that would be awesome.
Part 1: https://www.youtube.com/watch?v=H_DuGUu03N0
Part 2: https://www.youtube.com/watch?v=nD53ObIVBgQ
Part 3: https://www.youtube.com/watch?v=9IFj3D_cD28
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Mourning
As the situation of tragedy is a situation of separation and / or loss, you will mourn. Mourning is overwhelming, and although it may seem strange, it is a tunnel that you have to go through, because if you don't, you get chronic depression. Immersing yourself in mourning leads to you having to follow the 4 steps of the recipe. You're going to feel terrible, but there is good news. The mourning fuel tank is limited in size. The fuel of mourning is finite, it runs out. Mourning lasts from 1 to 2 years, and is initially more intense and decreases in intensity over time.

Each person has a different level of tolerance to these emotions, and there is always the possibility of seeking medical help. Science at the service of your well-being.

There comes a day when you feel like you are locked in a room full of a deep boredom that comes from the soul, because you are already tired of being sad and feeling bad, and you only have one way left: to feel good and be happy again. That day the fuel tank of mourning ran out.
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FORGIVE
When it comes to mistreating loved ones, especially close relatives, it is very painful. But it happens in many families, from the rabble to the most renowned families. Why should you personify those who, having the DUTY to love you, do not?

Imagine that learning to truly love was something you learn in a school, there you learn theory and practice. There are no schools, so all the love that people learn to give is learned from generation to generation. So if they don't love, they are emotionally illiterate. And when you start to see families where there is no love, you discover widespread illiteracy. Grandparents did not teach parents to love, and they could neither love nor teach their children love. And if you do not learn to love, you will be one more in the chain of illiteracy.

You cannot require an illiterate person to solve astrodynamic equations. Nor can you ask someone who does not know how to love, to love. That is the reason why you should forgive them, for being illiterate. But that also means that if you do not get out of illiteracy and do not learn to love, you will continue to suffer from the lack of love. You would have to become the first PhD in an illiterate family.

From a realistic point of view, abusers are idiots, because they preferred to have dopamine instead of having love. Finding someone who truly loves you is hard. In their late years they will be alone.
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IMMEDIATE ACTION
Abuse requires silence. Abuser will try to cancel and silence the abused. It is like escaping from NK. Check Youtube channel of Yeonmi Park and see what I mean.
It is important to put as much distance as possible, like you would do between a lion and a deer.

Hope it helps.