Loss at the same time as change and culture shock

Hello everyone. Sending good wishes to all. I must say I have read through some posts, I am only a new member. And my greif feels incomparably small. However, I shoulnd´t think like that because everyone has a story.
Here´s mine
This time last year or a bit before, everything was perfect. I had a job i liked where I was constantly developing, I was doing my Masters, I shared a place with a friend and, more than anything, I was completaly inlove with my partner. I am only Young, but I felt I had found the person I wanted to spend the rest of my life with. And he felt he had too. We were completaly in love and very happy together, but the main thing was that we were close Friends. We trusted each other, supported each other and understood each other.
Then , almost completaly out of the blue, every element that made up my beutiful life which i was so greatful for, fell apart one by one.
My housemate and friend verbally attacked me and threatened me and my partner with the police for whatever reason that i still cannot understand.This caused a trauma based on the fact that I couldnt understand what happened, she was one of my best Friends. I lost my flat which I still had to pay for. Due to financial complications I had to resort to going to the small claims court. Shortly after, I lost my Masters due to a department error and all the work i had done during the year. And before I knew it my relationship went up in flames.
Out of desperation I moved in with my mum, in a different country. I was new to everything, i didnt have the documentation to work. So i spent every day inside the house, lonely and desperate.
But all this was just warming up. It wasnt until I discovered that my partner was a cocaine addict that everything truly went downhill. he neglected me and didnt want me in his life, he would spent nights drinking and snorting and get sick. His parents would worry and communicate with me.
About a week after what would have been our anniversary, he started something with another girl. I thought we were going to be together forever.
Unfortuntaely it got worse. He made random contact with me when he was drunk or high and said different things each time, post break up. he was a different person. I finally decided to free myself from feeling like his hostage and, when he decided to créate a new social media account just to harrass me again, I warned him i would go to the police if he didnt stop.
We havent spoken sicne.

The hardest part is still missing him, and thinking about him every day. Even though he was unstable and abusive. How do i deal with this inner conflict?