Take a gander at my Article on love languages, if you haven't already.
http://www.bellaonline.com/articles/art10664.asp Since the sex has been good, there may be an element of the Physical Touch language in there. And the saying "I love you"? (Or lack thereof)...doesn't mean there isn't love
there.
What are you guys fighting about? If it's petty issues, then what's underneath? Maybe your fighting is a way to attempt to achieve intimacy (as odd as that may sound). Some people use arguing to get closer to people...especially if they're afraid to be vulnerable.
Keep talking to one another. Ask questions of each other. Questions like "What do you need? What do you feel you're not getting? Where do you want to be in life and in our relationship right now?" Provide an atmosphere for honest and open sharing, without taking things personally and reacting to what is said. Maybe one of you could go first, and the other must be silent until all that needs to be said, is said...without interruption or fear of retaliation.
Just a few things to get your started...
I hope this helps!