I think your 1st step would be to convince her thoroughly that you indeed still LOVE SEX, think about it all the time and very much desire to get back into it with her -regardless of the obstacles you face, even IF it just means pleasing her.
Have you deeply shared this with her?
It is very unfortunate that you backed away sexually when you did , instead of taking the reins and just pleasing her then. This is what inevitablly brought about her "loosing her drive"-cause she felt you lost yours. Sounds like she loves you very very much to marry you, being aware of all of this, then adjusting her drive to accomondate what what happening -or not happening at that time.
Not sure about her, but some women, myself included, if I feel my husband is just trying to please me -and he is not fully into it with me, I would not like or enjoy the experience very much. In fact, It would upset me. I want him to WANT it too, even be a little SELFISH about it ! I want to feel his "need".
Not sure how long this "blocking out sex" period was for you & her, but it may be an uphill battle to convince her fully that YOU are INTO IT AGAIN, full force, you are lusty, you are erotic. Maybe she needs to FEEL that to kickstart her drive again.
And learning other alternative ways to please each other. I found this book on amazon that might give you ideas Amazon.com: Let Me Count the Ways: Discovering Great Sex Without Intercourse (9780874779561): Marty Klein, Riki Robbins: Books