Loneliness is a state of mind... This is what I try to tell myself anyway, laha! But seriously what about all of us on Christian Chat? I'm lonely too so feel free to talk to me!
And who says that you can't have fun by yourself? I personally like going to the most boring places for fun (museums, libraries, play, etc.) I take myself on mini dates and enjoy being able to not worry about anyone but myself
On the less selfish side, definitely helping out in the community is a GREAT way to fight loneliness. This is because it gives you a wake up call on what lonely and being alone is (which are too different things believe it or not). Yea, community service is definitely good.
Also pray and grow closer to God (which is the way to fight everything, and hey your by yourself, you have plenty of time!)
When you don't have anyone you get to know God very well... I know but trust me when I say this is true! People my age get annoyed by how much I know and can quote scripture. What can I say?
"His mouth is most sweet, Yes, He is altogether lovely. This is my beloved , this is my friend, O daughters of Jerusalem." (Song of Solomon 5:16) A mate of the verse being Psalms 119:103.
Pray for friends and have others pray too.
"Even when I walk through the darkest valley, I will not be afraid,
for you are close beside me. Your rod and your staff protect and comfort me." (Psalms 23:4)
God is always there with us and the Psalmist makes this very clear Psalms 139.