Ok so from what I gather you already have the required backup for the photos ... best bet right now would be to DELETE ALL from camera roll then use iPhoto to create Events/Albums and sync them back via Photo option in iTunes
Now to delete all from Camera Roll is a bit tricky as iOS doesnt allow it..
What you can do is use iPhoto or Image Capture app on a Mac to IMPORT all photos from the Camera Roll ... and after import, the app prompts you if you want to remove all the imported ones from the phone ... just select Yes and you are done

(You can of course remove these imported ones from the app)