What am I doing here?

Everytime I have a high point in my life it seems to be followed by days sometimes weeks of feeling depressed. Depressed to the point that I don't want to get up,or do anything; thats when I ask myself what am I doing here. Your told when your young right and wrong, what to stay away from and what won't hurt you. Told that the meaning to life is finding what makes you happy, but the problem with that is, what makes me happy is tearing me apart. I realize that I think about what makes me happy more than I spend time maken it happen. I've always been a dreamer and maybe being a dreamer is just that, nothing will over come of a dream. I tell myself that everything will be ok and to put a smile on for the people who are around, but that smile in reality is a frown. Maybe the problem is being told lies all along, the lies that there is love out there and once you find that love, happiness is right around the corner. Does it actually happen like we are told, or have people just put on that smile to make other people happy, when deep down they are depressed too. What are we all doing here? What comes of love but a heartbreak in the end, rather your left for someone new or left alone when that loved one passes on, in the end heartbreak never fails. It will always happen to the hearts of the ones who try to love, who need, seek, and desire it. For me its to late to turn around, for I have one of those hearts.