Is this depression that I have?

Yes, go see a doc. I've had the same thing happen to me recently, its NOT normal behavior. It's depression.I was told that the human race is a social race. We naturally want to be around other people and wanting to be alone isn't normal. Loss of appetite and lack of sleep is another warning. Your doc will most likely put you on anti depressants and they take a few weeks to work right so set up an appointment soon