Here's more on the trauma bond and the addiction, that I found on Quora - it sums it all up perfectly!

HOW TO BREAK A TRAUMA BOND:

First things first. What exactly is a trauma bond?

A narcissist has a pattern of loving and caring, alternating with abuse and neglect.

These emotional ups and downs cause an over-exposure of mood-altering hormones to the partner's brain.

The brain then becomes addicted to these hormones.

Which, in most cases, causes the partner to return to the narcissist over and over again, to experience that emotional high.

It's a genuine chemical addiction to oxytocin, serotonin, dopamine, cortisol, and adrenaline.

Aside from the physical addiction, the patterns of behavior in the love/hate cycle, reinforce codependency in the partner.

By giving affection in small doses and alternating those doses with long periods of abuse and neglect, the narcissist keeps the partner continuously engaged in the pursuit of love.

And that's why people “try so long” getting a narcissist to love them. It's a pursuit.

Now, how to break that trauma bond:

You need to recognize and really grasp the fact that your relationship is built on exploitation, not love.

Your codependency is causing you to make excuses for the narcissist and allowing them to continue abusing you.

You aren’t helping them by staying in the relationship, nor are you helping yourself. You can’t change them. Ever. They're incapable of change.

These are the things you need to understand and continue reading about and repeat to yourself:

Narcissists are disordered, they suffer from NPD. It's an incurable disorder.
Again: It's a disorder. It's, by no means, a reflection on you or your value.
The narcissist didn't love you because they're incapable of it. They suffer from NPD.
This was never personal. Narcissists are disordered and the way they treated you, is how that disorder manifests.
Your pain is caused by a physical addiction to hormones. Not by heartbreak.
It's a chemical dependency, not love.
It's created by the narcissists hot/cold behavior.
Like with any chemical addiction, you're going through withdrawal. And yes, it would be nice to give in to the craving. But it's destructive and will only hurt you more.
Like with any chemical addiction, the pain and despair will dissipate with time.
Like with any chemical addiction, you're gonna have good days and some bad days. They come out of nowhere and it's all perfectly normal.

That's all it takes really.

Understanding wtf is going on.