So I've been talking to this guy for about a year now. I'm 18 and American, he's 20 and British. During this past year we text, snapchat, ect., almost every single day, as well as skyping once a month or so. We both have admitted we have feelings for each other but don't want to make anything "official" until we actually meet in person, yet we are "exclusive" in the sense of neither of us are dating other people or looking. In the past weeks he isn't answering any of my means of trying to contact him. I'm scared I've done something wrong, though the last time we talked everything seemed fine (that was almost 2 weeks ago). I care about him a lot but I don't want to play this game of him ignoring me and me worrying about him. I've never been in a relationship before and although we didn't put a label on it that's  basically what this was. I'm really worried about him and slightly frustrated with myself for letting myself fall for a guy who I haven't met in person and lives 4000 miles away. Any advice?