I'm 23 he's 34

I have been dating this guy for a year now and I'm not sure where it's going to go. See he is 34 and I am a 23 year old college senior. He's a captain in the army and he was just promoted closer to where I attend school. He has cooked me dinner, taken me out, layed up and watched movies on his couch and talked about everyday life. The last time I seen him physically was in December of last year, but we always keep in contact every other day and sometimes weeks we don't even communicate. When he texts he'll send messages like "I miss you" or "Thinking of you", send me pictures on what he looks like on that day and he also shares with me his accomplishments as well. He recently received his doctorates as well, so he's very successful. My mother thinks that he's just waiting for me to graduate college to take our relationship to the next level. He expresses to me all the time that he's not seeing anyone else, but I don't really believe that. I really like this guy and I think we can do great things together but I just don't want to keep holding on to something that might not happen