I really hesitate to reply, feeling like such a newbie but I keep reading this and thinking how I reconnect with my husband when we start to feel unsettled. We've been together 12 years too but I frequently still feel bowled over by love and excitement at being with him.
We have shared a lot of new experiences together over the last 2-3 years (the time when we've been most connected and happy) and I think they add excitement to being together and make it easy to meet each other's needs. I think more in terms of the emotional needs from the book His Needs/Her Needs by Willard Harley than I do in love languages now but they're a similar concept.
I really need a lot of conversation, honesty and openness and a lot of physical affection to feel in love/loved and my husband needs sex, to have fun together and for me to do domestic type things for him. Actually I really need sex too lol.. but thats beside the point because I'm trying to say that its really hard to start to try to meet your partner's needs when yours are going unmet, but its a negative spiral and sometimes you can get it back to a more positive spiral by finding it within you to meet their most important needs whether you feel like it or not for a week or two.