First, rule out anything medical. Have you discussed this with your ob/gyn AND family doc? I say this because I talked to my ob/gyn for years about this, and he just sort of waved me off. When I mentioned this to my PCP, he did all kinds of blood tests and just seemed more concerned and thorough in an effort to rule out any hormonal imbalances.
Second, are you on any kind of hormonal birth control? It's not just the pill nowadays that contains hormones. If you are, discuss alternate non-hormonal BC with your ob/gyn. The pill killed my libido...I mean killed it. I got more enjoyment out of rubbing my forearm than sex for years.
If none of these things apply to you, and you are in love your husband, in love with your marriage, everything else is what you want and are otherwise happy, counseling is an option. You could try things yourself to get that "spark" back. These boards helped me tremendously. I just read and read and read, lol. I got off the pill, picked a Saturday night, bought a few nice bottles of wine, made a really nice, romantic dinner, watched Lady & the Tramp (I'm a Disney romantic) and initiated sex myself. This was after two years of not having sex..even before the two years, it was maybe once a year for us. DH was truly blown away and so happy.
I did it again the next weekend. And the next. At first, it felt kind of weird and new, but it's been about six weeks now and we're starting to feel like a normal couple again. I hate to use the words "force myself," but I just knew I needed to do something. My DH has always done everything in his power to keep me happy, and I just felt I owed him the same.
There is hope! We've been enjoying our Saturday nights so much, I think I'd like to add a weeknight in there, too
Try and remember way back when what things used to turn you on (wine, dinner out, movies, whatever you are/were into), and pick a "good night" to incorporate a few of these things to help you get into the mood. Honestly, for me, it was the change in DH the next day. He stood taller, smiled more, touched me more, had a sort of skip in his steps, held my hand again, blushed a lot. I really loved seeing him so happy and so loving, so I figure I can do this!
BTW, we're in our mid 30s, no kids, met in '91 and married in '98. I switched to a different type of pill right after our wedding which I think affected the libido. Whenever I'd mention this to the ob/gyn, he'd say it's a common thing right after marrige
Good luck and keep me posted