More than a month has passed since I posted here, so it is time for an update.
As I type this, i am sitting in front of the fire place, with D at my right and Jarvis at my feet. For the past month, I have been trying to back off, and give Jarvis his space. I have been trying to pay more attention to his body language, and only pet him for a few seconds at a time (or until his ears go from forwards to sideways) when he comes within touching distance. I am still picking him up briefly every day, but this is no longer upsetting him, as he gets a treat right after i put him down, and I only hold him for a few seconds at a time. He is still running up to say hello to me when I get home, but he is now giving me a head butt, which is really nice, and while I can't report that he is cuddling on my lap, the distance between Jarvis and me on the couch and floor is decreasing. He is more frequently coming I am still learning to read his body language, but he seems less nervous and as a result, more interested in spending time together. I have taken the advice offered here, and when visitors come over, we are letting Jarvis approach them at his pace (or not) and that seems to be working better. There are times when he never comes out of his room when guests are here, but there are also times when he comes running down the steps to say hello to our guests. over all, he seems more relaxed and more confident, which makes me happy, so thank you to all who offered advice.