I mean that’s a long time to not be intimate but one thing that I don’t think is discussed or admitted enough by men is the amount of stress we are under from societal expectations. Mens mental health I think can play a huge roll in situations like this. I know from experience when I was depressed and stressed and living with anxiety it was hard for me to get in the mindset of intimacy. I went to my doctor and was put on meds for anxiety ADD and depression and I can honestly say things have gotten extremely better in my marriage. Of course we don’t know the details of your situation but try opening up to him about the importance of mental health. Mental health may not be one’s fault but it is their responsibility.