Ex friend

[Li****]

Hello. I am 22 and i am student. I would like to share my story and hear your thoughts on this topic.

I met this student in university at first year of my studies. I will call him N. We were talking and hanging out very frenquently in first days of studies and we shared common interests, had a lot of themes for talk etc. Time has passed and all was well for us. We were inseparable.. we would go out eating together, walking together, making trips and future plans together... we have become really good friends. 
However, on may past year (we were finishing 3rd year of studies) all has gone wrong. As i was living in apartment and him in student dorm, we were usually hanging out at each other's place. On that day, it was around 11AM, he was at my place and we were finishing some project i had been working on for university. He started insulting me for no specific reason and we started arguing about some minor stuff. However, after i told him that he can't talk to me in that way and asked him to leave my room. He did what i thought he wouldn't do in my whole life.. he assaulted me. He pushed me down on nearby couch with all his strength and when i got up he started hitting me with his hands. I defended myself as i could and i barely pushed him away from me. While i was catching breath, i looked at skratches on my hands he made me when assaulting me. I was scared and furious at the same time becouse i couldn't go to university like that to present this project in that state and more importantly, that he assaulted me. I shouted to get out or i would call the police, but he was just standing near the door and insulting me, which i responded by getting phone ready and using bottle of water near me to get him out of my place. He quickly grabbed my hand and had me fall on the floor, hitting my head on nearby table (fortunately my head got without any injuries) and he managed to break my finger while i was falling. As i was laying on the floor trying to get concious, i remember him telling me: "oh come on, stop pretending just get up!" When i tried standing up, i didn't feel my little finger on right arm at all, i couldn't move it. I was in shock and he started shouting at me like it was my fault that all of it happened. When i told him that i will call police to arrest him, he knew that was going to happen and that he can finish in jail for what he has done. I told him to get out and leave me alone. Soon ambulance came and we went to hospital. He called it and went with me there without my consent. While i was waiting for report, he was waiting near hospital. When the doctors told me it is serious place where the bone broke and that even the surgery is risking, i just got out to get some fresh air and try to calm down. I informed my parents what has happened and they were driving to my student city where i was. When i and N returned to my apartment to wait my parents, N started crying and apologizing to me, saying he loves me more than brother, that i am special in his life and that his life without me isn't the same and that he doesn't know what he has gotten into him to do that. I told him to shut up and that he can stop sobbing becouse i won't tell my family what has he done to me. Not to save him from their wrath, but becouse of former years that were good and more importantly, to try to save everyone from further conflict between families. I decided to sacrifice myself for that solution which i meant in that moment was the best one. 
When my parents came, they were barely holding themselves together after they saw me. N was also there, calm as nothing happened. They immediately asked how that happened which i did not respond quickly. They asked him and he told them he doesn't know. I made up a story at the moment that i slipped and broke it while i was falling. It seemed they believed but i sensed they were suspecting something else happened. They then unknowingly thanked shameless N for "being there for me in that moment" as he was smiling and telling them he will always be there for me. This is where i coudn't stand it anymore and told him to return to dorm as my parents were driving me to capital city hospital for further analysis and treatment. 
He was sending me messages to ask how am i etc. in later hours, days, weeks, but i didn't answer it. Even if i did sometimes, it was very short becouse i coudn't stand him for realizing with what monster and psychopath i was hanging out this whole time. 
Time has passed, summer vacation also, i was going on treatments but the pain, both psysical and mental was intense. He gave up on contacting me anymore during summer vacation. Concerning my injury, even now after more than 8 months i go to the doctors to try any way we have to repair that finger and completely mend the place of trauma. 
When 4th year started, N was also there. We weren't communicating but as it was necessary at minimum as we were unfortunately still collegues. We were functioning also as we had been together in groups for projects by professors. All was going ok till N started making problems in my life again. He made up some stupid excuse to accuse me of lying to him and saying bad things about him to other our friends at university which is a total lie and i even told him that even if i didn't have to do that. He than started making a scene in dorm, which i ignored, he started saying bad things about me behind my back to our other friends, and i sensed something is wrong these days between me and some other friends like they were distancing a little bit from me and i am sure that shameless person is behind it.. who knows what lies he has told them about me. 
I am so confused why is this all happening, why i did not told my family everything from start, why can someone be so monsterous, ungrateful and hateful without any reason. 
Please try to understand me and give me some constructive help and i hope no one gets this to happen in his life. Take care and thank you.