The appearance of distance can take place in any relationship even seasoned ones. The fact that after 4 months he had said he needs a break is not unusual (people get used to each other, tension may build up, pleasing and impressing the other person is not longer a priority so, it happens)
What also can happen though, if the two people are mutually invested in the relationship they both look for ways to improve it. It may be that he is trying to sort things out.
However, it is not respectful to hide the fact from others that you are his partner.
Change is a very hard thing for many people when they start a relationship. They may feel that their freedom is threatened. There may be many speculations as to why he had done so. The best way to find out is to confront him. Try to keep your expectations realistic and know that you like any one else is worth of being loved and being happy. When a man wants a woman he does not let her go or at least makes an effort to at least give her some explanation.