Lonely days...

Do you ever have those lonely days, or lonely weeks, or even lonely months?  I could be surrounded by people I love and still feel incredibly lonely.  I have been back in Cambodia for a week now, but school hasn't started yet.  At times, I tend to forget why I am here.  I lose sense of purpose, and my heart wanders aimlessly.  It is in these moments that my heart finds itself desperately lonely.  Jesus, please be enough for my hungry heart.  When I'm not doing something useful, I find myself anxious.  I shouldn't have to always be doing something to find purpose, or should I?  Lord, help me to find a healthy balance between serving You and resting in You.  Remind me why I am here, and satisfy my longing heart.