I need more practice
 

These days I has have been lazy and has have not practiced English.

My husband came back home before the Chinese New Year.

("My husband came back home for Chinese New Year" sounds a little better. We usually don't say that someone came home before a certain holiday because the "for" usually implies that he came back in order to celebrate the holiday, which means that he came before the holiday began.)


His company is in another city so he spends a lot of time on business travel traveling for business trips. We don't have spend much time together.

(We don't have much time together sounds like he will be leaving you for a long time in the near future or that he is on his deathbed. Usually we say it like, "We don't have much time left together.")

When he is home, I'd like to spend more time with him and less time studying.

However, I found that my ability to use English had has dropped dramatically. It is surprising that once you stop learning, you will not only stop getting progressing, but you will also slip back start to regress.

Has is better to use here because you are talking in the present, currently your progress has fallen. If you were talking about the past you could use "had". For example, "Last year, I found that my English abiliy had dropped dramatically so I did everything I could to make it better." Also if you use "had dropped dramatically" it sounds like maybe your English is better now since your English ability was poorer in the past.


Chinese has a saying: studying is like sailing against the current; either you keep forging ahead or you keep falling behind.

To make a verb a noun you must add "ing". "Running is my favorite sport." "Watching birds is one of the most cherished memories I have of my childhood".

Make sure that spaces go after punction marks, never before. 

I have promised myself that I would will study harder than before, and my husband has promised me that he would will move his business back to our city as soon as possible. I hope both of us will keep our promises.

You want to use "have" here because it is a promise you have made that is continous to the present. 

"Will" is better than "would" here since this is a factual statement that has been made. "I will do this" or "I will do that." Would makes it sound more like a possibility. "I would study if I had more time." "She told me she would have come if I had given her more advanced notice." "I promised myself I would study hard, but in the end I gave up trying" "My husband promised me he would move his business back to our city, but it turned out to be something he couldn't manage to do." etc... So usually some type of possiblity that could happen or was not able to happen due to certain circumstances. 

I need more practice

These days I have been lazy and have not practiced English.

My husband came back home before the Chinese New Year. His company is in another city so he spends a lot of time on business travel. We don't have much time together. When he is home, I'd like to spend more time with him and less time studying.

However, I found that my ability to use English had dropped dramatically. It is surprising that once you stop learning, you will not only stop getting progress, but also slip back.

Chinese has a saying: study is like sailing against the current ; either you keep forging ahead or you keep falling behind.

I promised myself that I would study harder than before, and my husband promised me that he would move his business back to our city as soon as possible. I hope both of us will keep our promises.