Stress?

My big girl may be having some signs of stress. Last year around this timing, she had a 'stomachache' problem. And after that very very bad enzema. And after that her concert day. And now she is having this no reason loss of appetite, tiredness, and stomachache. Exactly same as last year problem, and around same timing also. Next friday is her graduation concert. I brought her see doc today, but no sign of any problem. And for the whole day she was quite active. But when comes to night time, she became very tired. Then in the morning also very tired. But when she knows she is not going to school, she will suddenly become back to normal. Except for appettie. Since last night she has not been eating. She is not having fever, but body a bit warm. But sometimes in the morning, when i sent her to school, her hands are very cold and face n lips very pale.seems to be very scared. And just now i ask her anywhere pain, she say dun have. But she went to bed very early. 8.30pm she went into the room herself, and very quiet.i guess she is having some stress in school. Most probably is her concert. Really dun know how to manage her stress.