I have 2 iphoto libraries and duplicates of everything

I set up my macbook pro wrong 2 years ago and am suffering for my stupidity.   I have 2 iphoto libraries, both with different photos in them.  Last week I imported photos from one library into the other and now I have 56,000 photos, most of which are duplicates.  I have deleted about 20,000 - folders were duplicated several times.  New folders contain 'face' photos (just heads, from the face identity bit of iphoto but now as an individual photo).  What I want to do now is to restore my iphoto to how it was 10 days ago because i can't cope with the number of duplicates i have.
I have selected folders and chosen duplicate from the drop down menu but this just gives me MORE duplicates, it doesn't get rid of them.  I have bought photo sweeper app which is meant to show duplicates but this has made no difference to the library.
Can anyone help me either restore my library, get rid of duplicates or anything else?
I am not great with the compuer, so I need simple mac speak please


To merge libraries use iPhoto Library Manager - http://www.fatcatsoftware.com/iplm/ -  or Aperature
To find duplicates within an iPhoto library use iPhoto Library Manager - http://www.fatcatsoftware.com/iplm/ - 
Photos that are not in an iPhoto library can be imported telling iPhoto not to import duplicates (an imperfect procews) and then IPLM can find the duplicates
As to keeping seperate libraries - only you can do that - IPLM can move photos between libraries for you but only you can know which photos should be in which library