sgh-t619 memory help

When i first got the t619 and checked the shared memory, it had 30mb available
Then i started messing with it, like trying to install java games using the guides on the internet, but gave up after my phone crashed and restarted several times

After that, when i checked the shared memory, it only had 20mb available, even though it didn't transfer anything


I think there might be something hidden in the memory that isn't showing up when i check my memory status

Is there like a way to completely reset the phone? like to clear the memory and everything?

10mb just disappearing from a total of 30mb seems a lot..