In my experience, the 'love' we feel in the first year or so of a relationship is often giddy, energetic, ebullient. As time goes by, it's hard to sustain that. Things settle down.

I think it is easy to mistake that settling down for a sign that something is wrong, when really it is just a natural progression in a relationship.

I hope you two can work things out. I found it really helpful to talk to other people who had been in long term relationships.