Friendship is a necessary human need. Your state of mental well-being is affected by the mental state of those around you, in particular family and friends with whom you have frequent contact over a long period of time. It is human nature to need association with friends.
Seek out people with positive thoughts and lifestyles and get to know them. Reach out to communicate with friends regularly. Invite others and meet with others as often as you can to build a group of friends. Eat with friends, share your food with friends. Help friends, and ask friends for help when you need it. Learn how to develop friendship and how to respond to the social dynamics within a group of friends.
Support your friends to help keep them in a positive state of mind. Work to maintain lifelong friendships. As friendship develops over time, one gains trust and the friendship strengthens to the point of one's friends being almost as important as one's self.