I got a problum with my laptop and i need help.?

well i was on facebook then my pc just froze so i restarted it and when turned on it said startup repair, so i let it do its thing but it says may take over an hour to complete but its been 5 hours and its not doing anything and there is no way i can go back onto my laptop because it wont start up it keeps saying attempting to fix repairs pls help i need my laptop for school and it's not working.