lied on the first day of my job

So i recently started a new job as a waitress in a restaurant which i love, however i feel like i have already ruined it as on my first day the manager asked was i here on the Monday for training, i panicked and said yes and followed on with that lie, i feel extremely guilty. He is paying me for coming in when i didnt and im now too deep in the lie to confess to him that i didnt work that day. Im scared that he will ask the trainee if i was there before paying me as he already had suspicions when asked what i had been doing. This is causing me deep anxiety to not go back to the job already, i feel stupid and panicked in the heat of the moment.  Any advice would helps thanks