"It feels like I'm talking to a friend, not a girlfriend..."

I've been with my (now) long distance boyfriend for over a little over a year. The other night he was acting a little quiet, distant, so I asked what was on his mind. He resisted before finally saying, "y'know, you joke around and I'm frustrated because it feels like I'm talking to one of my friends." And I'm a little surprised because to me we were being normal, a couple. We talk about our day and we say good morning and I love you. We support each other. And he continued to explain how it felt like I wasn't being affectionate enough, though I feel as if I've been expressing a lot of affection and love as I try and stay close to him when we now live so far apart due to college. I feel like a failure in some since, like no matter how much I try he won't see my efforts. He seems to gloss over it. Now I can feel as if he's planned to break up with me, and it hurts. Any advice?