Rédaction d'anglais

Bonjour, j'ai une rédaction à faire en anglais, d'environ 400mots.
Sujet: Write an imaginary anecdote about your psycho-ex. What a terrible misadventure happened to you?

Je ne dois pas faire forcément quelque chose de très original, mon prof note en fonction de l'orthographe..C'est pour cela que je vous demande votre aide afin d'éviter des fautes.

Voici ma rédaction. Merci d'avance.

I known him since summer holidays, we had very pleasant moments together. Everything was fine between us, we learnt to know us. We saw us every week when we didn’t work. We went to cinema, we eat ice creams, we have a good relation and we talk during hours.

Then we have to go at school on September and we were in the same class. In the beginning I was happy and smiling. It was the beginning…
Generally I was near him in class; we both were serious and dynamic. Everything was fine and we helped us for homework.

But, one day he started to make strange things. At the beginning, I didn’t notice anything. I realized that he was constantly stressed before going in pause. Then, I didn’t see him and he came back a few minutes later. I asked him what’s happened to him but he didn’t answer to me. I didn’t understand and I started to be worried. One day I decided to follow him after the lesson. He was going in the toilets. I surprised him making a scary face, he was very nervous and I was frightened. He didn’t know that I was just next to him. He took something in his bag, it was a toothbrush. He started to brush his teeth very quickly and nervously during a long time. I believed that he never stopped, he was red and he started to jump in all directions. I ran to return in class, I was very chocked because he was my boyfriend and I believed that I was knowing him, but I was wrong. He returned in class too, after me. First, I didn’t look at him, and then I asked him: “Are you ok?” He told me “Yes of course”. He was totally fine and became concentrated.

The next day, he started again. He became stress and disturbed. I followed him, I wanted to talk to him but this time he started looking at him in the mirror and he became totally crazy. He said strange things which had no sense. I didn’t understand what he said; he was talking to himself with a very strange face. He had a very amazing attitude; he was just look as if he was possessed. Then I tried to talk about his stress before the pause but he never answered to me. He didn’t know that I have seen him and that I known about his troubles. He started to become more and more troubled and he talked to me aggressively. One day, we were talking about music and at once, he screamed at me, he said that I was a stupid girl and he kept going to get berserk, he was extremely nervous and then, he ran at his home. I didn’t understand his reaction. The next day, he didn’t come at school and I have never seen him again. I tried to call him and to go at his home but I have never had news from him. He disappeared from circulation.

This boyfriend was very very strange and incomprehensible. I always remembered it because he was out of the ordinary.