Starting out alone on a long distance tour doesn't mean you're going to be lonely. Of course, some of that depends upon your temperament and personality. Even if you ride long distances alone during the day, you can interact with locals freely, if you choose, at rest and meal stops, and especially at campgrounds. (Stealth camping, not so much
. I always enjoy meeting locals. For me, it's one of the best parts of the touring experience.
Invariably, I also run into other touring cyclists along the road or at camp, even off the beaten path. If you're heading in the same direction you might choose to ride together for a few days or even weeks--but it's your choice. That's the freedom of touring alone. Touring alone means the pace is yours, the frequency of stops is up to you, the choice of camp vs. motel is yours, etc. It sounds pretty self-centered, but sometimes touring is the only time to enjoy a little "me" time. I'm not saying this is always the way it should be, but sometimes it's necessary to spend a little time with ones' self. And share the experience with those you meet along the way, and of course, at home. When you do return home your loved-ones will notice that you're like a new person. And probably, you and everyone around you will be better for your experience.
FWIW, I've only done six tours with friends or family and they, too, were amazing.
Enjoy your tour,