How can I express it?

As the composition that I wrote last two days ago stated, I quit my job last April.  I came moved to Shenzhen to study two weeks ago, in order to have a better English learning environment. I am living in my friend's home, who with me was attended the same collage as me. However, she was an English major and I was majored in Japanese. The My friend is traveling in Thailand for a week. Last night I had a QQ conversation talked with a person I met on italki, who lives in Thailand people who from italki in QQ . I tried to explain to him that why I didn't go to Thailand with the my friend. Can I say it as written below:
I came to Shenzhen not so long ago (just two weeks). Before I had decided to live in her home she had already made the plans to travel to Thailand and had already booked a plane ticket, so I didn't go with her.

You are very brave to make such a big change!  I hope to do something similar to learn Chinese.  Your grammar is overall pretty good, you just need a little more practice and your English will be great!  加油！