How to convince someone you love them

My DS is the eldest of my 2 AC. Now in his 40s he is single, independent and reasonably well off. He lives 150 miles from me. I live near my DD and my DGS with whom I spend a lot of time. My DS was always jealous of his sister as a child. He resented her coming along and taking up my time - at the time I had no help from anyone and she was a demanding infant whereas he was quiet. But he and I have always had a good relationship and chat regularly on the phone, sometimes for up to an hour. But I rarely see him. He is always busy with work or friends or off somewhere on holiday. Part of the reason he doesn't visit much I think is that he still resents his sister but what can I do about that? I live near her so it's obvious I'm going to play more of a part in her life than in his on a day-to-day basis. Basically I don't think he has ever accepted how much I love him. I do fear that he is somewhat cold like his father from whom I'm divorced and that it's just his nature. But I miss him and before I pop my clogs I'd love him to know how much I loved him as a little boy and how I love him and am proud of him as a man although I have actually said this to him more than once. He had a wonderful fiancee for many years but ended the relationship and, since she has been off the scene, he has become more distant. I think about him constantly but it seems he's quite happy doing his own thing and seeing me is a duty rather than a pleasure. I get quite sad about it all. I'd love him to really realise how much I love and care but, if I wrote it in a letter, I think he'd be scornful. Perhaps it's his nature. He rarely wanted to be cuddled when he was young. And yet, on the rare occasions when we do spend time together, we never stop talking and have a lot of fun. Maybe one day if he ever has a child of his own he might understand. What do Gransnetters think?