lack of hand independence/coordination at piano. plz help :(

When you understand that you are asking brain/body to grow new brain cells and pathways perhaps you can be more understanding/forgiving and patient with the process. Sometimes these things take a lot more practice and time for those new neural pathways to be made. Sometimes it just doesn't happen.

Practice with doing scales is a predictable exercise; however, performing a piece with all those less than predictable changes is quite hard.

For example, here's a classic 2-hand independence exercise: using your left hand, rub your stomach and with your right, pat your head simultaneously. Now switch hands.

This activity/exercise can't be done successfully by 95-98% of us. With practice, you can better at it...but most of us can't master that exercise. This piano-playing you are attempting is analogous to that.

You might try some of the suggestions here:

http://music.stackexchange.com/questions/3215/how-can-i-significantly-improve-my-hand-independence-on-piano

and here

http://takelessons.com/blog/piano-hand-coordination-exercises

Tha k you very much your advice have been very helpful

Thank you very much I appreciate it ^.^