There are two types of pain physical and emotional pain, as far pain acting inside the brain it was shown on mri scans that the same areas of the brain light up regardless if you are talking about physical or emotional pain.
The purpose of emotional pain is to alert you when there is some tissue damage that occurred, this could happen in multiple ways like through impact or high heat, infection etc.
The purpose of emotional pain is to alert you when you are experiencing certain loss, this generally happens either through being a subject to violence as a motivator to do things that are unfair for you or through being lied to, there are also natural causes that could lead to loss it is not all the ill intention of other people that causes loss things like disease or death will also cause emotional pain.
Also the pain in itself can be of two types acute and chronic. The purpose of acute pain is to let you know when there is some damage that just occurred in order to prevent further damage, for example if you break your arm that is what would represent acute pain, it generally at the beginning of the trauma and it tends to stop or get better when you stop moving your arm. Acute pain will stop when the wound is healed, either the physical wound like in the example of the broken arm or in the case of emotional pain through the process of grief that generally last somewhere from 3 to 4 months after the trauma, after which the person that experiences the acute pain regains his functionality and the pain subsides.
From the experience of the acute pain, under certain circumstances it can become chronic pain. There are two circumstances that can create chronic pain. Acute pain becomes chronic pain either when you are constantly re injured like for example if you hit the corner of a table with your leg everyday and get a bruise that bruise will never heal until you don't stop hitting the corner of the table. The same is valid with emotional pain if you have someone in your life that is constantly lying to you or that subject you to violence often enough you will never heal until that stops.
The other circumstance under which acute pain becomes chronic pain is when after the repeated re injury has stopped the pain still persists. As a result of being subjected to pain for a long time you actually become more sensitive to it. Pain behaves the opposite pleasure does, the more you experience pleasure the lees exciting is going to become, like if you eat your favorite food everyday you are going to enjoy it less and less. Pain is the opposite the longer you are exposed to the traumatic experience the more damage you are going to suffer, so your body produces an adequate emotional response to motivate you to get out of that situation.
If you put your hand in to a fire the longer you hold it there the more severe the burn is going to be. Pain has to be worse than death because the purpose of pain is to motivate you to avoid dying in that regard living your life in pain is worse than being death. Like this you become hypersensitized to the pain and you over react to small relatively non harmful situations.
When emotional pain becomes chronic it is no longer just grief it becomes mental illness, all the label modern psychology puts on people, is for the attempt of the people that are suffering from chronic pain to control or escape the pain, regardless if you are talking about: depression, anxiety, OCD, bipolar etc. behind all this symptoms there is chronic emotional pain.
It is like being in an airplane with broken flight instrument that are telling you that you are going to crash in to the mountain when in fact you are flying over the clear sky. This in itself can disrupt your life and make you disfunctional, the purpose of this is to avoid retraumatization if you actually think about it, regardless the fact that you are dysfunctional it is a great survival strategy it is not a great lifestyle or way of living a full life but you are at least alive which is better than being dead.
The common wisdom regarding emotional chronic pain that comes from having a hypersensitive response to stimulus is generally to expose yourself to that stimulus in order to desensitize yourself until your brain realizes that you are overreacting to that scenario. What is most commonly called facing your fears. This is a paradox because the more pain you experience the more sensible and reactive you become to it. It is like trying to lose weight by starving yourself, the less you eat and the longer you stay on your diet the stronger your impulse to eat become and the less energy you will have to fight it, until you just brake off and just go on a binge. So all the progress goes down the drain because it is close to impossible to fight your impulse to don't eat.
The same happens with pain the longer you stay in that situation that triggers it the more intense the pain becomes and the less energy you will have to fight your urge to run in the opposite direction. So at the end you just end up with a lot of memories of you failing and maybe some small amount of inconsistent results and often relapses. This method works very scarcely and has a very high rate of dropout.
So what is the solution!?
The problem is not necessarily environmental as much it is an internal brain problem, where you formed a very strong neural connection that fires very efficiently when it comes to pain in certain circumstances, in order to reduce your hypersensitivity you have to weaken that connection.
Lakely the brain remains malleable enough for the most part of your life, so this can be done at almost any age no matter how many years ago did the trauma happened.
It is like when you take a long break out of practicing any skill you that ability is going to start to atrophy. The brain works over the principle if you don't use it you lose it.
Of course stopping strong emotions and impulses it is close to impossible, after all that is the purpose of an impulse, it is like the emergency button that overpowers everything and change it's course. So what you do instead is to replace it with something else, no matter how intense the emotion or impulse a small part of your brain remains conscious.
You can compete by using that small conscious part of your brain in order to slowly disrupt those really strong connections. I have had success with visualization so far every time my pain would com out I would just visualize something for just a couple of seconds. In the beginning this won't give you a lot of pain relief the first day you attempt it at best just a couple a seconds, but the more you do it the weaker thouse connections become so by the time 30 days have past I was pretty much pain free.
The name of the game is persistence, you have to be as persistent as the pain, every time you feel the pain visualize something it really doesn't matter what you visualize. The goal is not instantaneous pain relief as much it is the long term goal through slow accumulation that will eventually desensitize your brain to pain, so you can become functional again.
