I really think loneliness is more to do with how you are feeling about yourself and your life. You can be in a relationship and feel lonely and you can be on your own and not feel lonely. As i said i was single for 18mths then got back together with an ex, then was single again for 18mths.Before i met my current partner i was really happy being single, i was not lonely. i changed so much in that time and resolved many issues i had. I knew i would never again be in a bad relationship. i would rather be on my own. I had saved for years and i took my son ( then 3yrs) travelling to see a close friend in Australia and my brother in China as well as travelling on our own. It was life changing, not only the experience but the fact that we did it, the two of us, on very little money.
And now saving for another trip!
Like you said, do things you enjoy, learn new skills, if you can then travel, and read, there are good books like Feel the Fear and do it anyway by Susan Jeffers, Manhood by Steve Biddulph (good insight into men!) The Power of Now, not sure of author.
good luck x