I'm 12 years old and I don't laugh or smile anymore.

I'm 12 years old, I used to be very fun and enjoy sports, but then suddenly I stopped playing with my friends at school or talking to them. Nothing makes me laugh anymore. I have no reason to show my smile, so I don't. I know I'm very different from the normal children, I don't know why I'm like this, but I think I might be depressed. I do know I'm depressed, I just don't want to admit it to myself. It's hard to admit that you are depressed. I don't know how I should express my feelings.<br><br>I don't really know what I'm looking for on this post, maybe a miracle to make me smile or laugh, maybe a way to help myself, or maybe a friend. I don't know.<br><br>What should I do?