What Does It Mean To Be Happy?

I know others have it worse off than I do. But does this mean I cannot grieve over my own life. I know this makes me sound bad, but just because one has it worse off than the other does not mean you cannot be sad about your own life. 

What does it mean to be happy? Is it the love I see when I look at the only person who loves me? Or is it the disgust I get when I gaze upon my broken mother and distant brother. 

My friends have long since abandoned me to my own mind and heart to tear myself apart. Happiness. Comes in many different ways. Mine comes in the relief of the blade, the knowledge that I am alive and the love of my soulmate. But tell me, is this true happiness. What is happiness and why is it so important..