Why? Why! Why...

I feel strange.
Why do I play badminton worse and worse?
I play it almost every Friday and Saturday.
I'm always practicing it!!
The first time I played badminton here ,
I didn;t play well,
'Cause I Hadn't played it for 2 months.
After, I played well , very well again.
But recently,
I felt that I'm losing my skills.
I don't know how 2 play,
I can't smash Like Lin Dan or Taofik Hidayat.
I can't apply strategies to it, or even I've no strategies sometimes.
I hate myself being like this.
I'm supposed to play very well.
I wanna practice from my coach for several yrs until I'm quite skillful.
I miss my perfect performance in playing badminton in China!!!