I hate to butt in on the ladies forum but I want to give my $.02. As a man (and I can ONLY speak for myself) I HATE it when I wife has sex with me "just because I want it". If she's not into it, I can tell and I am immediately turned off. I want my wife to want me (one of my reasons for losing weight) and I want her to be into our love making. It means too much to me to cheapen it by making it mechanical or obligatory. Maybe my wife is just a bad actress and I am very glad about that because I don't want her to "fool me" into thinking that she wants me. And it makes the times that we DO make love so much better.
I agree with what the ladies have already said. It seems like from what you're saying, you are focusing on yourself so don't feel guilty about that! But have you found a way to communicate your goals to your husband? Is there any way you can bring him into the process? Make him feel like he's contributing in some way and he won't feel left out. For me, the littlest things go a long way. Show him that you appreciate the space that he's giving you and how much it means to you. Things may have changed because of your surgery, but make the change be for the better. If you really love him and want to make it work, there is no such thing as "over-communicating".
Sorry for interrupting ladies. I have no idea why I keep wandering into the powder Room...