Am I in the wrong if so what should I do?

Lately (last month) me and my wife have become severely emotionally detached. Despite my best efforts , she just shows no interest in me. I'm an EMT I work a minimum of 48 hours a week in 4 12 hour shifts I also work nights. It's the only shift I could get it's not by my choice. I'm the only money maker in the household she stays home with the kids 3 of which aren't biologically mine but I took them in and treat them in as my own, we only have one child together. In the last 4 weeks making love has dropped of to one time a week if that. I try to talk to her about and make sure that she's still attracted to me and to see if I've done anything to make her lose interest in me but to no avail. She won't even cuddle in bed with me anymore on my nights off, she's getting frustrated why I keep asking why we never make love anymore, she's keeps asking why it always comes down to that subject. And I can only think because it's the only time I get to be close to you anymore! She's making me feel pigheaded that I just want to make love to my wife! I bring home the money I cook the family dinners I treat her kids as there my own flesh and blood I give her all the love in my heart I make her breakfast in bed I help with the baby I let her know everyday that I love her and I think she's beautiful is it so wrong to want to make love to her every now and then, I mean damn I'm a grown *** man I have needs too does my happiness not matter am I wrong what should I do different is there something I'm not doing does it sound like she's mad at me?