Sounds Like you need power auras classic.
this will allow you to track any debuff / buff on you or your target, either all of them, or your own only.
I have mine set to show an icon when when my debuffs are not on the target, and when i get specific debuffs.
It can be quite daunting to setup the first time you use it as it is quite complex about what it tracks, but once you have got the hang of it, it is quite possible the only addon you will need to track your debuffs or lack there of on a target
Power aura's is highly configurable, from what icon or text to use, to sounds when your buffs / debuffs drop off.