Aurora, so sorry no one has responded. I have no children myself, but remember so well when this happened to me with a breakup but my mother was there for me. Of course she told me I was young and someone else would come along and I didn't believe it or want anyone else, but I know her heart ached for me too.
I think what you are doing--just being there for him and giving him hugs and telling him how much you do ache for him will help. It sounds so trite to say that time will heal, but it does. I remember the hole in my heart and the feeling that nothing but that person could repair it and it didn't happen.
Why does it have to be so painful to love????