Can someone please help me with grammar and my words this is very urgent ?

i am trying to write very important paper which is based on a imaginary story i need to check my grammar because i know i have several problem i dont have enough time can please someone just help me on this ..

This is my paper :

I was best when it came to punching and boxing but this time I was going to compete in one of the biggest tournament that I always had dreamt for. I was training hard, sweating hard and I had significant improved after year. I was much faster and I had better kicks and I could defense much better but I still wasn’t satisfied with income and I was not able to picture myself loosing this tournament .This was tournament that I was waiting for very long time and It was very important to me and I wanted to do everything to win this tournament, But there was a problem ,someone was not letting me picture myself as Champion of this tournament, something that was not letting me to sleep at night and If I was going to sleep ,He was waking me up by nightmares .He was no one’s but my fear , fear inside of me , fear of losing, fear of not winning . Someone from inside me was telling me i can’t be Champion of this tournament and i was not able to imagine myself loosing this tournament.
I knew an old friend who used kind of magic injection and made best out of different tournaments but that magic injection was nothing but drug which called steroid, but I didn’t care if it was drug or not so I decided to pick up phone and call this old friend and ask him if he can help me .when I called his number it seemed number was changed and number was out use. I was confused I didn’t know what else I should do. after weeks search I could finally find my magic injection, yes I was happy , and I started injecting that magic injection into my innocent body , yes I was seeing and feeling changes much faster , and it seemed everything was going so much better .I was feeling so good but because of changes in my body but because I was not hearing my fear who was not letting me sleeping at night or waking me up in middle of night by nightmares anymore yeah I was happy .

So it was last week before my match I was never in better shape that I was at this time but I was feeling kind of pain with my heart, I had no idea why I should get some pain with my heart but I was really very happy which I was not even wanted to think about it and only think that I was caring it was my coming match.
It was last week before my match. Around 11 at night I started going to bed however I felt I can’t breathe I felt I am sweeting strangely which was very weird, after some minutes struggling with myself I felt nothing but darkness, and when I woke up from that darkness I saw myself in middle of hospital, I was confused why I ended up at hospital, yes I had heart attack, and yes it was because of those disaster magic injection which I used to inject it.
I was still in confusion so doctor came to me and explained to me how lucky I was that I am alive now, and he told me about other guy who passed away couple of weeks because of same problem that I am struggling now at this hospital, he showed me picture of the guy and when I saw picture I found it out reason why my old friend was not able to answer my call because he was the guy that doctor was telling me about.
I was that blind that I tried to ignore all these side effects. But now it was too late for me to choose between fear inside of me and magic injection because I was at hospital, and my long time waiting tournament was already passed.