this is what worked for me on my samsung galaxy note 2 Android 4.2.x

# unsync photos from google, facebook, etc.
1)SETTINGS-> Add Account * (this should be right above SYSTEM area of settings)
make a written list of all the accounts you have synced with your device
((go back))
2) SETTINGS-> [name of account from the add account list] -> Sync intervals settings -> set these to none where photos listed
3) SETTINGS-> [name of account from add accoount list] -> click on your username/name -> Sync Gallery [ ] <= uncheck

# clear thumbnails off your phone
4) once you are done doing this for Facebook, Google, etc. go to...
SETTINGS-> Application Manager (slide the filter along top to ALL)
find Gallery and click on it
press the "Clear Data" button
press the "Clear Cache" button

# share, post, and view images without problems
ENJOY having a fast gallery !