And I thought that I was the insecure one all the time... :s
Of course, the ladies have their doubts and feelings of insecurity just as we do. I think the best way is to discuss it as openly as possible. But then I always want to discuss things in the open with my friends and girlfriends, I am just no good at pretending. Sometimes that can come across as "too honest" for some and be misinterpreted. Just like Maxx says, though, try to show her those little signals now and again and remind her what she means to you. Tell her. Also, tell her about your plans to visit her, how your Chinese studies are going and let her know about the preparations for the trip, step by step, when the time comes.
Early on when I started writing letters to my lady, I brought up that I was cheated on before and that this had made me more careful. She told me of a similiar experience she had had and suddenly we could both share our feelings of insecurity and fears of not being good enough for someone or being cheated on.