Loneliness, despair, self-isolation can be the sign of mental illness. So many young and old and in-between are suffering without knowing that it is possible to overcome these states of mind.
There are people who dedicate their lives to helping the lonely, desperate people who think the answer is to lock themselves in their room; stay in bed all day; or just wander off into the darkness with the hope of finding the light.
The “light” for me is God, but it can be different for everyone. Help is available. Do not despair! Seek your light. It is within reach!