What is going on with him?

He has been out of state for a month now. When ever i say i miss him he says aww but never says i miss you too. Same thing when i say love him. He smokes pot even though he knows i don't want him to. Sometimes i know he is high while he is talking to me but he can't admit it. Other times i want him to be affectionate but he says he can't. Recently he started saying "let me call you back because... Blah blah blah" but he never does. He can't even talk about anything on the phone. I don't ask for much. I just want him to show he really wants to be with me and that he cares... Am i just over reacting?