Sooo stressed

ok so heres my situation, i am severely ADD and i do home care. i faxed in my time sheets today for payroll and now they want me in the office tomorrow to talk to the location manager because i had a slip saying i worked on a certain when i didnt, i had my weeks mixed up, had i realized that i would havwe never ever done that. now i feel like they think i was trying to deraud them. hhhheeeelllllppppppppp ami gonna lose my job over this?
Just be calm and be honest -- you sent in the wrong slip amongst the right ones. An honest mistake. Explain what happened and apologize for the mix-up. You aren't going to insist they pay you for work you didn't do, so they should understand that it was an error.