You are suffering from depression. I am too. I'm sorry to hear that you are going through this my friend. Let me tell you something - negative thinking releases bad chemicals in your brain which causes sadness and/or anger. When you catch yourself thinking negatively, stop it immediately no matter what. Thinking negatively is the root cause of depression. I don't know if my answer helped, but I hope it made you feel a little better. :)
Drepression is not an illness just a state of mind. Find out what makes you depressed or angry. Then work on healing your emotions or overcoming it. I was in your situation but now I have realized that life is beautiful and to love is awesome. Also look for things that make you happy, life is wonderful and too good to waste. There are solutions to every problem in life. Try to find counseling that can also help.