Loosing Interest

My boyfriend and I are 4 months deep into the distance and let me tell you, being away from his is harder then I ever expected it could be. And it's even worse when I feel him becoming more and more distant every day. Some days we hardly talk and when we do the conversation is becoming stale. I fear he is loosing interest in me completely. I a already booked to come Visit him in 2 more months and it can't come any quicker. Do any of y'all who have been through similar situations and pushed through got any advice? I would really appreciate it. Thanks ladies.