I think you have been pursuing the two avenues open to you and I'm sorry it hasn't helped, all I can think of is following the therapist route. They are not all the same and it may take a while to find one able to help, if that is the problem. I don't know that it is. If you don't believe it is, maybe a second opinion from another gynecologist could help, at least a different perspective on suggesting where to find help.

You had no desire for sex for a year before you got married, was there a time afterward when you did have what you consider a normal drive? If so, what changed? 

Physically, did it just disappear one day or gradually? Why do you think it's no longer there? Without knowing more, unless you two can work on it together, that's the third option, a therapist is probably the best chance if nothing is wrong physically. Wish I had the answer.