No, I don't believe in karma. I do believe that the choices one makes in life determines what happens to them, though. And I believe that if we keep making the same choices, we will keep getting the same results.
I think you have what I have, which is called "Black and white thinking." You may want to Google that term and see if anything pops up that helps you to change your thinking. Or, you can work with a therapist on changing this kind of thinking. You know what they say, and I am a true believer, "Change your thinking, change your life."
Try your best to live in the Present Moment and let life happen as it happens. I know, easier said than done. I myself have been stuck in the past, and crying, and letting it control me for months now.