Mandela, though he was in solitary confinement for much of the 27 years he spent in jail, came out of it spiritually and mentally unscathed. And we have a suicide epidemic, if you'll believe the press, of people who were never in jail, and were surrounded by people whom probably could have helped the person.... provided he or she asked for help rather than deciding they were lonely or alone.
I'm not saying loneliness isn't real... all I'm saying is, it is a choice that needs to be recognized as such, even if we keep choosing it over and over and can do no other sometimes.
So if you feel lonely, unless you're in solitary, please at least TELL SOMEONE how you feel... if nothing else. Tell me, I'll listen.