What the hell is wrong with me?!

So, I've been dating my boyfriend now for 5 1/2 years. We are sexually active, but usually I only have sex because I want to make him happy (always consensual, no worries there). Don't get me wrong, sometimes I'm the one that wants to have sex, but that's like once every 3 months. It's not like he pushes for a lot of sex, it's more like maybe once a week. He's good at it, listens to what feels good and what doesn't and I orgasm every time. But, I never find that I outwardly want to have sex?

What the hell is wrong with me? I have a great guy that is willing to pleasure me in any way that I want, and he is pretty hot, but I have 0 sex drive.... what can I do to fix this?!