A health matter, not a private embarrassment
Two things worth setting down at the start. Loneliness is treated in the research as a serious health factor, which is the reason it is worth working on rather than a reason to add a new worry to your evening. And the Qur'an records Yaqub saying that he takes his grief to Allah, said out loud, to his sons, in the middle of a conversation. Naming what you are carrying is not complaining.
Qur’an and Sunnah
قَالَ إِنَّمَآ أَشۡكُواْ بَثِّي وَحُزۡنِيٓ إِلَى ٱللَّهِ وَأَعۡلَمُ مِنَ ٱللَّهِ مَا لَا تَعۡلَمُونَ
He said, ‘I plead my grief and sorrow before God. I have knowledge from God that you do not have
Qur’an 12:86
Translation: M.A.S. Abdel Haleem, The Qur'an, Oxford University Press, 2004.
What the research says
Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D (2015). Loneliness and social isolation as risk factors for mortality: a meta-analytic review. Perspectives on Psychological Science, 10(2), 227 to 237 doi
A pooling of many long running studies. Loneliness, social isolation and living alone were each associated with a higher likelihood of dying during follow up. The authors flag two limits themselves. Studies measured loneliness and isolation in very different ways, and poor health also reduces social contact, so cause and effect cannot be cleanly separated here.
Valtorta NK, Kanaan M, Gilbody S, Ronzi S, Hanratty B (2016). Loneliness and social isolation as risk factors for coronary heart disease and stroke: systematic review and meta-analysis of longitudinal observational studies. Heart, 102(13), 1009 to 1016 doi
The same pattern for heart disease and stroke. Lonely and isolated people had a higher rate of both over time. The authors flag the same problem with how differently loneliness was measured from one study to the next.