mistakes made on first day as nurse

today was my first day as a LPN working by myself. everything was going great even minor things like passing meds too slow or running out of floor stock of chewable aspirin didn't phase me. but i really screwed up by forgetting to do IV antibiotics for a Pt whose only there for that reason. he's alert X30 and reminded a nurse on the 3-11 that he didn't get it and whats going on. im completely frazeled and just wanna quit it all i dont even want to go back and the charge nurse called me to ask why i didn't give it. I forgot to give it because im not ceritified and i had to delegate the task to someone else and totally forgot. i feel dumb lost and second guessing nursing. i really jus want to vent to people who might understand. (thats the only mistakes i know of so far i know my documentation wasnt up to par)
At leasr you didn't get fired right? what do you mean ur not certified to give the iv antibiotic. LVNs can hang meds just can't give IV pushes.