Check your battery. Is it dangerously low such as <20%? Touch Contacts>MENU button>More>Display Options. Touch Phone and make sure everything has a RED check.
OTOH, if your phone did an UNWANTED Factory Reset you are in deep DuDu.
Actually it may turn out okay because an update to Gingerbread will become available 11/29 and a full factory reset before updating could be good thing. Also, some folks on this forum have said you may be able to manually download the update BEFORE 11/29.