Short story! Could you please help me correct this?

Hi, I have a very important written test tomorrow so I was just practising my writing, since it's something I haven't done in a while!

I took this excercise from a sample paper, I'm supposed to write a short story that ends with the words "He had, after all, survived. He now had a future to look forward to."

Could you check this short story for mistakes, please? Specially the sentences in colour, those are the ones I'm most doubtful about. I'd be so thankful if you would!

I wrote:

While the first rays of sunlight were shining through her window, X had just finished making her bed. Even though she hadn't had a good night's sleep, she was oozing with energy that morning.

She was moving quickly through every room in her big and beautiful Victorian house. She was now thinking about what she was going to have for breakfast. "I'll make myself some scrumbled eggs", she said outloud - and this you may found odd, but it is nothing strange to be talking to yourself when you live on your own, just as X did. But not for very long. It was in that same week that she was to be married to Mr. Y Z.

Y was a very young gentleman, and even more so he looked. However, he was a wealthy man and the owner of a magnificent estate, where he kept plenty of antiques, since this was one of his passions.

At at around 11 a.m. X left her house and headed to her future husband's estate. This was to be completely unexpected for him, for he was spending his leisure time with his mistress, Ms. W.

X enetered the place ever so quietly, since her intention was to surprise his beloved Mr. Z. But perhaps she had been too quiet, for no one heard her enter the room.

She had never been a witness to such an unpleasant sight. She felt like never before. She took one of Y's dearest old guns and slowly approaching to the couple she aimed at Ms. W's head. Before they could see her, the bullet was out, doing away with her life instantly. But Y always kept a gun under his bed and instinctively took it and turned to where the gun shot had come from, only to find X holding his very own gun at his face. It was only a matter of time. Y was quicker and shot her right in the chest.

He was so desperate. He was devastated to realise he had just murdered his wife-to-be. He lay by her side and wept for a while. Then he stood and phoned some of the wedding guests to inform them it was all off - of course he did not tell them why.

Despite the crime he had just committed, he felt relieved after all, at the thought it had been self defense. He was full of hope. He had, after all, survived. He now had a future to look forward to.

Thanks in advance!