What could cause a guy to not want ?

My guy and I have a good relationship. I love him very much and all about him. One thing, tho, i've noticed is he has no drive. He's very attentive when it comes to hugs, kissing (hot kisses) and maging and whatnot, but we hardly have . It's been over a month now. He says I turn him on, and he thinks I'm y (said he wouldnt even kiss me or hold me if he thought I won't y). But he just is never wanting . He does work weird hours all the time. One day he could work 12 hrs then have to come back and work another 8 hrs, 6 hours later. Could being stressed and tired make him not want sex? How could I get him going again? Is it me? Many thanks if you can help!