Pretty damn good. Depression is lame. Whenever I feel sad I go through a little cycle. I reflect on my past successes and possible future ones. I keep my goals in sight and always try to do nice things for my friends. The other day I made teacher appreciation week posters for my favorite teacher, and over the next two days I am going to bring in cookies for all my classes. I also keep my life filled with music and try to surround myself with positive people. I also try to stay smiling as much as I can.
And while I may noy have a girlfriend at the moment and that makes things somewhat lonely, it's really a trivial thing to be sad over. I'm only fifteen, there's still plenty of years to find a lover and take it from there. We're all insignificant creatures on a small dirt ball floating through the vast infinity of space. Why waste the short time you have in this life being sad? In a few decades it's likely nobody will remember who you are or anything you did. While that may seem depressing itself, it really isn't. Live in the moment, don't spend your life drowning in a pool of self pity. Try to constantly make other people's lives better!
As the Tralfamadorians say, try to focus on the better moments rather than the worse.