"Deep loneliness" refers to a profound feeling of being sad, isolated, and longing for connection with others. It is a strong sense of emptiness and absence of meaningful relationships or companionship. Full definition
For the still deeper loneliness of feeling at loose ends with the universe and devoid of any deep - going roots, only a religious outlook can work a cure. (religion-online.org)
That is, studies show that people unwilling to extend forgiveness to someone who has done them harm will often withdraw from social relationships and tend to experience deep loneliness. (relevantmagazine.com)
Feelings of emptiness, sadness, and deep loneliness after the object of our affection steps back or walks away are only a reflection of our own lack of self - love. (mindbodygreen.com)