It was a cold evening when a man trapped by the blue sweater.
He was in a hurry because his wife was waiting for him at a store to choose a wedding present. He rummaged for the sweater in the closet which goes well with the gray suit. He had trouble forcing his arm through the hole. Then he saw the ugly hand stuck out from the sleeve which finger looks wrinkled and bent inwards, like a black nail with a sharp tip. He quickly pulled his arm out of the sleeve to check what it was. There was the same hand as always.

He wanted to try other arm into the other sleeve out of curiosity. It was twice as difficult and suddenly he was surrounded by the blue gloom. He was trapped inside the blue sweater. He couldn't remove the sweater moreover the sweater got tighter so he couldn't breath easily. He fought with the sweater gamely.

Sometime later he suddenly felt cold air on his eyebrows and forehead, on the eyes. The cold atmosphere told him that he was "out". He opened his eyes slowly then saw the five black fingernails hovering over his eyes and he barely escaped from the attack of the black fingernails. He pulled at the sweater's collar upwards and ran twelve floors down where no "hand" and "sweater" exist but fragrant air was.

わーい。はじめて一番乗り＾−＾
最初読んだ時は、まったく頭に入ってこなくてどうしようかと思いましたが読んでいるうちに面白くなってきました。Amazing storyとかスティーブン・キングの映画に出てきそうな奇妙な話ですね。

This is the story about a man who was at the mercy of a blue sweater.
It's fall evening. He was supposed to meet her wife at a store. But before going there, he thought that he would
wear something that went well with his suit; he picked a blue sweater.
It was not easy for him to wear it.
First, when he forced his arm through the hole, his hand appeared to something weird, not appeared to his own hand, which made him think that he'd better to put the other arm into the other sleeve. It was the beginning of the misery. Because of the lack of habit in beginning by the other arm, that operation was much harder than usual for him. The more he struggle with it, the more his effort doesn't work out. For the meantime he was stuck in the sweater. Although he could have his head coming out after a long struggle, he saw his hand looking something other than his own again, so he couldn't help but pull the sweater's collar up. It brought him into that sweater again.
He might have been panicked and tried to escape from the sweater and the hand. Finally he reached a certain place --- 12th floors down after all.
You would never blame anyone.

初めての課題提出です。
話をまとめるって難しいです。
自分がポイントだと思ってまとめた部分が本当にその話のポイントだったんだか？って感じです。
こんなたくさん英文を書いたのは久しぶりです。英文作成が思った以上に大変で、内容自体にあまり時間をかけていないのですが、(英文も変なところたくさんありそうですが、)明日あさっては仕事なので、提出してしまいますね。

Once you get bogged down by something, it appears likely that you will have a big struggle to get out of it. If such a situation is caused all by yourself particularly, you can't blame anyone.  
It was six thirty and a little bit cold outside, so the man picked up a blue sweater to put on. He was in a hurry as he had kept his wife waiting for him at a store. He started putting the sweater on. That was the beginning of a big trouble.
Despite of his tremendous effort he couldn't wear the sweater, more precisely his weird right hand seemed to prevent him from wearing it.
He didn't understand what had happened to his right hand but when it came out of the sleeve, it looked like a black nail with sharp tip although it was his normal hand outside the sweater, which frightened him a lot.
He tried various ways to put on the sweater and got trapped in a blue web when he put head into collar and arms into sleeves simultaneously. 
Having struggled for quite some time his right hand went through the sleeve (collar?) first, and then the head managed to come out of the collar and felt the open air. However what waited for him there was the weird black fingernails again, hovering over his eyes. With fear he summoned up all his courage to run away from the sweater, the weird fingers, and this unlucky the thirteenth floor.

twelve floors downという表現にこだわり、彼がいた場所は「魔の13階」という大胆な解釈をしました。腕を通すと不気味に変わる右手もそのせいだと・・・。もっともこれは実際に13階ということではなく、比喩的に「不吉な場所」を表していると取ってもいいでしょうし、また彼がそういうふうに感じただけとも考えられますし・・・。

It's fall evening and cold outside. He has to put on something to go out. His wife is waiting for him at the store to choose a wedding present.
He picked up a blue sweater but it was not easy to wear. He was struggling with a sweater. More he tries to wear it, more it tangles up on his arms and head. His right hand came out however it seemed to come out sweater’s collar, that’s why he feels the collar is pressing so tight on his face. He barely breathes because his face is completely covered by the sweater and his face is wet with the fluff of blue sweater.
Even though he tried to put his left hand out with his right hand, it was impossible to handle the movements of both hands. The situation is like a rat trapped in a cage and another rat is trying to help it run away.
He wants to make one last effort to push his head out and the left hand out as he turning around in the room, he suddenly feels cold air. He fell and opened his eyes carefully. He put off his sweater and ran to his wife waiting for him.

こんなにもがいていたら暑くてセーターなんていらないでしょう（笑）落ちたかな〜と私も思いましたが最後は奥さんの待っているお店に走っていったのかなと解釈しました。