If you can't get home to family and friends have all made other plans or you are too depressed to ask them, go to a free meal at a church or shelter or community center. Mingle with all the other lonely people and it will help. Maybe they will let you help serve or set tables.
Speaking as one who has done that...
Reach out to social events in your area. Card playing groups or other activities that interest you.
A small pet also can help. I had a small about of this and got a chihuahua. It is nice to have a pet to be responsible for and he is so sweet.