Why won't he discuss this with me?

I have a male friend, we are both married and have four children each. What started out as a platonic friendship has grown to be a 5 year emotional relationship. We have avoided being physical, although the desire is there. We both know that we must honor our commitments and our families. I struggle with the emotions and the feelings and he does, too. For him, it's easier to avoid talking about it. For me, it would be easier to discuss the situation and talk it out. I guess I need his support in letting go of the emotions. I need us to both let each other go, but be able to do it with support. It won't be easy to do, but knowing we've done it together would be helpful to me. He is shy and doesn't feel comfortable discussing it. Does anyone out there have any suggestions? I'm trying to do what is right, but save the friendship and make sure we are both in agreement and feeling good about what we've done.