always struggle for life, GOSH....

Suddenly... I feel so doubtful bout my life.. my future...

This moment I really doubt of everything. What will I reach? what is my dream? what will make me happy??
One thing accomplished didn't mean a happiness, but it only bring us into a new duty, new difficulties, new pressure.. n of course.. many new problems!!
What should I do?
If life's only for struggle, how can I smile?
How can I feel happy in reaching anything if I know that it's juz a beginning for another stress??