As a guy who's in almost the exact same situation as your man right now I think he would understand that you need time to yourself. So he thinks highly of you? Why wouldn't he? He's going to think the world of you as you're the girl he wants to be with. Nothing wrong with that. If you are scared to lose him then tell him what he means to you and show him too, don't run away or else he's going to think that you don't want him anymore and then he's going to be left more confused than you. The best advice I could give is to be open, honest and communicate. Never be afraid to lose something, you will be scared to make new memories and won't enjoy your time together, cherish it while it's still here. Remember that as sad as you might get he'll be there for you to try and put a smile on your face