Less than one hour before she died, Hannah did a Google search on "depression help".  

Earlier that day she had said to me "Dad, I feel so sad, ... and tired, ... but for no apparent reason".  I thought to myself,  "It sounds like you might have depression", but I had no idea of what to say, or how to help her.  As a consquence of what happened that day, I became determined to know what I should have known back then, and when I found it, to share it with everyone.  I started my journey by asking the following questions  

1. What is depression?
2. What can a person do to help themselves if they are depressed?
3. What can I do to help someone who has depression?

Now, I am not an expert, and I am not a professional psychologist, so I shouldnt really answer these questions in such a public forum, but I felt that it was better to provide some information, than nothing at all. I am hoping that this little bit of information will motivate you to keep looking -  until you find what you need.

Depression is an illness that can kill.  At best, it can rob you of your freedom and many hours of fun. In its advanced state it results in the brain being unable to produce or properly distribute the neuro-chemicals required for clear and rational thinking.  However, it can be treated and need not cause you any harm. People who get depressed at some point in their lives, can recover to live long, healthy, happy lives.