Number one in managing loneliness: stand on your own legs. Realise that true happiness comes from inside not from outside, find meaning in just being alive.

Second is family, parents until 30's and then your own. Wife, kids will always be there, either on Wednesday night or on Christmas. You will give no f for others.

Third long time friends in decreasing time scale: high school, college/uni, work.

Fourth you reach out any club you find, from mushroom lovers to blind date lovers.