Some ideas, or notions - from a perspective which sees current arrangements as extremely bad and contributing to vast misery and despair.
I am implicitly referring to able-bodied men in decent health, who can work and make a living.
Given that it is generally much better to be married and to have children; what about those men (and it would mostly be men) who do not marry, do not have children - and whose lives are therefore celibate (as the ideal)?
1. Do not live alone. People are not meant to live alone: it is bad for them.
If you have one and if possible, continue to live with your family. If you don't or can't, then live communally in some kind of structured environment (like a college, boarding school, the military or other community). Or with a group of friends or similarly-placed men. At least have meals together.
But if no such thing exists, as is usually the case, the prospects are indeed bleak. Finding some such environment should be a life-priority.
2. Work is not enough. Work and leisure is not enough.
You must be religious, and live a life of service in a (real) church if you are not to go off the rails psychologically and spiritually - one way or the other.
3. If possible and appropriate, befriend and become attached to some family or families that you can help in whatever ways they need, and where you can become 'part of the family' to some extent.
The life of a 'live in' servant of some type may be suitable (caretaker, gardener etc) as long as it is not solitary.
4. If you are a Christian with a 'monastic' tradition of the religious life, consider living in a religious community, and serving that community in whatever capacity they need - perhaps as a 'lay brother'.
The above list is far from exhaustive - but the problem for single men is, and doubtless always will be, a real one - and, psychologically, a big one.
Note added: I think the point I most would emphasize is that the single man must not make work his priority, and fit everything else around it. Nor should he live for his leisure: for weekends and holidays. Neither of those will be effective, and either may prevent him finding what he really needs. The strategic priorities, that towards which he plans and schemes, should be along the lines described above. For example, he might seek a job in a place where there is a good church, or to stay with his family.