Have you talked to him about what might be the problem, and been willing to wait for his answer? I wish I could be more helpful, but all I can say is that we haven't stopped trying. Communication is critical, but it can't be forced on anyone, and each person has to have their space to work out issues (this seems to apply most often to men). My husband and I have had some pretty severe breaks before, but one way or another we always find a way to open the lines of communication back up so that we can work it out. It's not always easy -- in fact, sometimes it's downright painful before anything can be figured out -- but it's always been worth doing.
One of the things that I've learned to do is no matter how angry or frustrated I am with my husband, or no matter how much what he says or does hurts, I stop and recall the feelings that I have for him and why those feelings are there. I find that this helps me deal with him with a more loving attitude, and helps me cope with my own emotions when things aren't going right. Remember, too, that some men act like they don't need love and affection when they really need it the most. There have been times my husband has been acting like a complete a**hole and will act very angry and say some very hurtful things, but then I'll give him a hug and he completely breaks down. There has been more than once when the thought of leaving has crossed my mind, and I just tell myself, "not today." Without fail, by the next day he's ready to talk to me and I've never been so glad I didn't act on the spur of the moment.
Give it some time -- married life takes some adjustment, and five months isn't long for things to settle down. No relationship is perfect, there will be tough times no matter how close you are, and it's basically just a matter of being able to work through those tough times and use them to understand each other better and find new ways to grow closer.