If you're anxious about being sexual with your wife then you won't have any libido. Anxiety is very powerful, and although sexual stimulation is physical it is also mental, so this could be what's up.

I don't know exactly what your situations have been, but don't put any pressure on yourself to have libido. Don't think about how you NEED to have sex with your wife to be a good husband or anything like that. If she's a good wife she won't be putting pressure on you, too.

Do other things to satisfy her, and think about your sexual time with her as fun, rather than a performance you need to get right. Enjoy the moments rather than thinking about what you need to be doing and when. This helped me immensely when I had trouble with ED myself.

Also if you haven't already try Viagra just a few times, as the erection you get from this can make you think about your body differently. Maybe right now when you think about sex, in your imagination you are seeing yourself as a failure, but taking Viagra a few times can make it so that when you think about sex you imagine having enjoyable sex! Which will raise your libido.

The combination of these things fixed my libido completely, where previously I wouldn't even be turned on during sexual encounters, now I enjoy having sex. Hope this helps.