To be honest I don't have a best friend, I have a few close friends but I often feel I can't confide in them as much as I would like.
I have found over the past few years the internet to be a great source of help. I enjoy talking with likeminded people about all sorts of things, from the trivial to the very deep. It's nice to be able to almost hide behind the computer screen, almost anonymously and ask for help and advice from other forum members. You find people often have more in common with you than you thought. We have the 'deep thoughts' section if you ever feel you have anything you'd like to talk about perhaps. I have found everyone to be very non judgemental.
In the meantime however, don't feel alone, you're never the only person who is feeling down and low. It's only temporary though like Alibi said, things will pass. My Mum always tells me 'it will look better in the morning'. Try and stay calm and work through your feelings rationally and I'm sure you'll feel better in time. Take care! Lots of hugs being send your way!