I have traveled solo several times; my DH takes motorcycle trips without me (which is FINE with me - I don't like them).
The key for me is to plan things you love to do, but at the same time be willing to alter those plans as you meet people. How long are you planning to go away? I can't imagine getting bored or lonely in a week or two by myself. I always have something to read (Kindle), and my travel journal to write. And give yourself "permission" to have down time. Slowing down and enjoying life doesn't have to mean being bored.
I went to Spain about 10 years ago (before DH) by myself. I toured in Madrid, Seville, the white towns, and over to Barcelona. I met up with some people I had been chatting with on the Lonely Planet forum in Seville, which was fun. And I got "adopted" by this one family for a few days. We met in line for a castle tour or something, and talked while we waited. Two days later, I randomly ran into them again in the next town at a café, and they invited me to join them for dinner. It was a lovely evening; they were a fascinating couple in their 50s with 20-something kids - all well-traveled and just nice people. I never would have had that experience if I was with other people, because we probably wouldn't have struck up that first conversation.
Two roads diverged in a wood, and I - I took the one less travelled by...