Expiry date?

Does every relationship have a "freshness" period? Will all the initial passion die off eventually? I feel that these days, we're not communicating, we're not in sync with each other anymore. Short temper and fuse surfacing. Things dun remain the same forever, but if this continue, i'm not confident that it will work. Things are so different when we first started. Silly things that made you laugh now become irritants that make you mad. Only about a year into the relationship, what will happen in the years to come? :(