Accepting you are stuck in hole at the moment, isn't the same as seeking out and desiring to live in cave; I think, heh.
Various people prefer solitude to varying degrees. I've known extremely social people, who, despite their social prowess, still tend to be kind of, 'loners,' in their own right. And I've heard about legitimate and actual hermits. This one guy in south America built a house, farmed, raised sheep, and lived completely alone, away from human being for the majority of his life. Once his age caught up with him, he was lucky to have a friend, who would come by and help out here and there.
The only place I'd know of, to learn more about a life of solitude, is to seek out information from the source: people who know about that; whether it be on the internet, or in real life.
Monastic life is quite solitary, in many regards, to various degrees; but, some monastic life is quite social, despite that.
As far as, 'acceptance,' of the pains of loneliness, there's psychotherapy, counseling, groups, advice and suggestions all across the internet.
One person here, posted a video, a long time ago, of a, uhmm, lecture, given by a Buddhist monk. One of things he said he did was, every morning he woke up, he greeted himself. He'd say something like, "Hello me." So, this kind of idea of getting to know ourselves; not really alone, even if we are alone. (I don't think giving ourselves a hug is quite the same as receiving one, personally, but there is something to be said for the idea of embracing the pains of our lives, to a certain extent.)
Some of the Christians will say that common prayer, "God grant me to change the things I canchange and accept the things I can not change, and the wisdom to know the difference." etc..
One interesting thing I've found is, some people, even if they have a lot of friends, and a very active and full social life and circle, is, they can not _stand_ to be alone. They simply can not tolerate it. And interestingly enough, I think people like this could often benefit most, from learning to do that: be alone with themselves.
And on the contary, there are those that perhaps have more to learn by being among others, rather than being alone.
So, there's a lot of information out there.
Sadhghuru, Ram Dass, Thich Nhat Han, etc.. All sorts of spiritual advisors and leaders, I'm sure, have their own take; from all different faiths, etc..
There are a multitude of Ted Talks on the subject as well. Probably a wealth of psychological advice, from those types.
The science of loneliness is probably pretty depressing to dig into. I don't think those of us who suffer from it, need to be told it's painful, and therefore, probably stressful, and consequently possibly deleterious to health.
