Jabjo, have you tried writing your feelings out for him to read in a letter? I feel very fortunate that I knew both of my parents loved us kids very much and both were quite willing to tell us. Mom died last January, but dad is still here and we never ring off without telling each other that we love one another. My kids and I do the same thing.
Sometimes, though, after I moved away for ten years and came back, I think my mother tried too hard or wasn't quite sure how to be with her all-grown up *baby*. I was a little uncomfortable, sometimes, when she would express her feelings, in person. She was raised fairly Victorian and I think some of that came to the forefront in her last couple of years. She and I began to communicate better by telephone and in writing than when together. We would talk for hours about the most profound subjects, death, god, religion, spirituality, politics, history, family dynamics, etc. She was always full of praise for me and saved the letters I wrote to her.
When I started writing my columns for real, she became my sounding board, hearing and critiquing every one of them before they went to print. The hardest thing I ever had to write and that she never got to read, but which I am proudest of, was her obituary. While I am content in knowing that she and I made peace and said most of the things we needed to to one another, I still would give anything to have had her here this weekend just to share the momentous events of New Years. She would have loved it.
I guess what I am trying to say is, try....if you can't say it, write it. If you can't bring yourself to send it, put it away for a few days, get it out and reread it, then send it or change it, but just do your best to communicate. If he is able, he will respond; if not, you will know that you did your best.