Hi Ghost,
I totally understand what you're saying. A long time ago, I used to have to try to find things to keep my mind off the emptiness in the house (and in my heart), but as time went on, I actually came to enjoy being by myself and choosing whatever I wanted to do. There are time, of course, when I wish I had that to share with someone, or that he would share his hobbies with me, but maybe someday!
The things that take up most of my time are work, attempting to exercise (does thinking about it count?!), church, and of course, I read and respond to a lot of threads here on CC. I've always been an early morning person, and one of my favorite things to do on a day off is to get up while the light is just breaking and go for a walk, so I can watch the sun rise.
I also enjoy writing letters, both through email and good old fashioned snail mail, reading, occasionally watching movies, and working on small craft projects. Right now I'm hemming a pair of pants for my mom, trying to put a zipper into a pair of shorts (a continuing adventure) and making some small gifts for a group of friends I plan to meet with this summer.
I also try to spend some time cleaning and keeping things organized, but you wouldn't know that right now if you could see my dining room table! (It's covered with papers, my Bible, books, and craft supplies.)