HELP! PS3 Fallout 3!!!?

Okay, so one day i was playing fallout 3 just fine and dandy, and i tried to go into tenpenny tower where i love to get some stuff, and the game froze up when i walked in the door! i tried probably 8 times, and it would start to load, then just freeze. so i looked online how to fix it and it said to go to Game/Game data utility/ Fallout 3 and delete it. so i did. and when i started the game up, it asked me to install the latest version of fallout 3, so i did. now Whenever i play the game, every single loading screen takes 10 times longer to load! I've tried cleaning the disk (i have a skip Dr. Disk cleaner) and i've re, installed that game data utility thing like 3 times. I have Mothership Zeta, and The Pitt for DLC, if that helps. But PLEASE! I Need Help!!!!