I was referring to how when a relationship has been going for a while it is easy to lose some of that energy that is inherent in a new relationship. Have you read anything about New Relationship Energy yet?
Also, as you know, women experience all kinds of ups and downs depending on what our lovely hormones are doing at any given time. The dopimine (someone please tell me how to spell that word as the spell check doesn't recognize it) levels when things are new can make romance and sex like a roaring fire. The trick comes in finding ways to re-fan the flames. I know it may be a challenge, but perhaps you and she can do something different than anything you have done together before? Maybe go someplace to try something neither of you have experienced before? From food to activities, it can really get the feel good hormones flowing.
There are far more knowledgeable folks here than me and I hope that more will drop by to give you some words of wisdom.
I think that the cultural worries about material stuff and success can really be a bear to overcome. I know how that is. No real words of advice though.
----I will remind you that there are many kinds of intelligence and that Katie wouldn't give you the time of day if she didn't see at least one kind in you.....don't you love how I know jack about her but I still say it? Well, I believe it is true.