According to Psychology Today, ways to reduce the feeling of loneliness include working on social skills and increasing interactions with supportive people. Additionally, look for positive aspects within relationships rather than focusing on the negative ones. Engage in self-affirmation regarding relationships and increase the time spent cultivating good relationships.
Loneliness can be brought on by thoughts about a deficit in social interaction or about the negatives in existing interactions. Adjust this thinking in order to increase positive social interactions.
If a person feels lonely in a roomful of people, it is important for him to consider whether the problem is the people in the room or with or the way he is looking at the situation. If the problem truly is with the people, then he needs to change his social setting. However, the problem is often simply how he is looking at the situation. If he surrounds himself with people who are inspiring and who treat him well, it is important for him to enjoy it and to stop looking for the potential negatives.
Smile more. Smiling shows confidence and attracts people, which leads to more opportunities for social interaction. This has the added benefit of instigating others to make the first move, which helps to avoid some of the awkwardness in new social interactions.