I heard a good analogy the other day that sometimes trauma or grief is like a ball bouncing around your inner walls, and every time it hits you feel pain. Over time the room is still there, and the pain still sounds, but the ball hits less.
Sorry you gotta live this suffering. Perhaps see it as not something you hate or feel sad about, but just a feeling like any other in this rich tapestry of life. When it moves through you, welcome it as an old friend. Happiness is not the be all and end all, just another thread.
I do hope it fades with time. Have you ever received any kind of therapy?
RE: Seeking Some Help. Do Traumatic Images & Memories Ever Go Away?