What is wrong with me? 15/Female?!

What is wrong with me? 15/Female?

Im 15 years old. At around 4 months ago I noticed this;

I am always tired
Ive gotten lazier
Ive lost interest in things I used tolove
I like to sit around and eat more (im not overweight)
I hate to socialize (ive always been shy)
Ive been wearing more black and my style has changed
I dont hang out with the friends I used to
Im antisocial
I dont have a love for things I used to
Im losing faith in my religion

I dont know whats going on. I need help! As for my lifestyle, I get at least 7 hours of sleep a night, I eat healthy, I play ice hockey and softball, I play elec. guitar. My mother has anemia and my dad has Chromes disease. Please, If you can tell me if I have depression, or its just hormones, please help.

4 weeks ago
I forgot to mention I am not on ANY medication or drugs/alcohol. Never have been.
Also, I forgot to mention that I am the only girl in my neighborhood who goes to a private school. I recently switched schools and I dont hang witht he friends form my old school who live in my neighborhood much anymore.

4 weeks ago
Another thing about social-ness, when I talk to people, especially adults, I cant look them in the eye. It makes me feel nervous and awkward. I also dont know how to do a conversation. I feel rushed and insecure, so i usually try to avoid talking to people.

Probably a poor diet- your brain functions only on what you feed it. Most teens don't eat right, and most teen girls are into dieting, so that makes it even worse.