Good vs.Bad

What a hell of a week.  I have been on a emotional roller coaster for the last 7 days.  While the low emotions have subsided, the thoughts and memories that accompanied those emotions have been camping out inside my brain.  Gloom, Despair and Agony on me!  (I know I borrowed that from Hee Haw) Why is it we remember the bad when we desperately need to focus on the good?  I want the good emotions to kick those bad thoughts asses.  Can they do that and still be good emotions?  Maybe they can. All I know is I need Divine Intervention!!!