Has something changed in your daughter's life? Friends moving or friendships ending or changing? Can she drop a class and take it in the Summer - this might take some stress off now. At 17, kids are going through a lot of changes and school work can suffer. Does she have an outlet - yoga, running, or swimming to relieve some stress? Sometimes we are so used to what is going on in our lives, we don't even notice the stress. Meditation can also help. It does help me get through problems and reduce the stress, and maybe it will work for her.
Do you have dinner together as a family? This is really simple, but it gives you time to talk and share and really does help to find out what is going on and to give everyone some much needed "down time."
I am sorry but Feng Shui is not going to help you. There are a number of things that could be wrong with your daughter. You can get back to Feng Shui once you have rulled out the onset of a neurological disease, drugs and pregnancy. I taught teenage students for 32 years. I am giving you good advice.
Feng Shui is only 1/3 of fortune - you have destiny (karma), Feng Shui, and man luck (what you do with your life).
A person must act on all three spheres to achieve success. Feng Shui issues do not have the personality change you describe.
When there are changes of personality and behavior in a teen, there is a crisis in that teen's life. What about her teachers? My daughter had a terrible time wth an abusive teacher - all improved when someone else was able to talk to her. your daugher may be the target of bullying or abuse. Neurological issues can cause personality changes; there is a lot going on her - checking it out won't hurt and can only help.
I know you love your daughter, but sometimes kids don't talk to parents.