Also another tip:
Don't put other game files on your PSO memory card.
From the experience of many it is known that the PSO file doesn't like other game files on her card
And like the others said take a break and then come back if you want to.
Really? *worries* Both my higher levels are on a card with bunch of other saves on it....

Dude, take a break. I did once. And when I come back it is still all addicting and good. Play some other addictive game for the moment. =D