i blew it !!!

i feel like givin up... i fasted yesterday, just drank water and exercised.... until my fiance ordered pizza!!! I HAD to get me a slice, okay honesty... i ate 5.... i know thats alot.... omg i started crying ! im so dissapointed... i shall try again tommorow.... anyway how much do you think i would lose if i ate only 1 Celery a day????? 45-50???? tell me ok thanks.