When does it end?

I have been depressed for a few months now maybe even a year and when i was diagnosed with clinical depression it almost locks you up and you feel as if you cant get out, like there is a black cloud following you and it is raining bad thoughts in your head. The worst part about my condition is that my emotions run through my family and my part of my family is depressed as well, im still a young man and with all this mess going on i feel like (as others do) useless and have thoughts that the world could really do better with out me, the only thing stopping me is my relationship with my family and how it will destroy them if i do decide to end my life. I want to know if its possible to get rid of all the bad thoughts and be happy again, im on anti ds i think they working but recently i have not been doing good at all and i dont see anything worth living for anymore even my dreams and goals seem to be blurred