In life, there are transitions with our experiences, and that is natural, also what is important is how one is comfortable with ones own self, and its also important to realise that one can't change oneself according to the needs of someone, as this happens by itself but not by force or demand. I suggest you talk to him, and work on your communications, see what is concerning him and how can that be addressed, or you may talk to an expert and take some counselling sessions.