when i accidentally copied a peer's sketch

soooooo like art school and we had this big project due on friday. i'm always behind because i get lost in my own sketches and totally forget about deadlines, yknow? well anyway, there was this one kid named liam who sits next to me and he's got these amazing skills that just flow out of his sketchbook onto the paper. every time i see him work, it makes me feel a bit... inadequate? but in like a good way, because seeing what someone else can do motivates you right? so anyways, last night we had our critique session and everyone was presenting their projects. i saw liam's piece up on the projector screen and just kinda stared at it for too long. turns out he noticed me staring and asked if i wanted to borrow his sketchbook to check some details or something. which is weird 'cause i would never normally do that, but i thought maybe...i don't know...maybe we could learn from each other? so i did it and when i got home, instead of starting my own piece from scratch like i should have, i kinda accidentally traced over one of his sketches. it's not even a full copy or anything just a little corner that matches up with what i wanted to do for my own sketch but couldn't figure out how to draw myself. now im super worried that if the teacher finds this out they'll think im some kind of art cheater or whatever and give me a bad grade which would suck cause i've been working really hard all semester, even if it is in my own way. plus its not like i took credit for his sketch either, just used it as a reference. so whaddaya think? am i the asshole here?