Dude, you know you have the skills and the qualities to have a flourishing social life. You are not socially impaired like some have been, so it is totally possible for you to get back to your old self and start enjoying life again.
I believe that with a little digging, you will brush away your coat of depression and loneliness. Sometimes it even takes just a hint to pull you out, and start being happy again. Hope you do it mate