firstyeargrad

i am halfway into the semester and i am having a difficult time in my classes. i take responsibility for my poor performance (i certainly could have studied harder), some of it are things out of my control (adjusting to a new state, dealing with homesickness, then a family emergency.) the worst past is that the phd program i'm in is kind of a do-over of the stuff i did as an undergrad - it's to ensure that everyone's on the same page. there are even undergrads in some of my classes and they seem to be doing ok. so i KNOW that i can do this. or perhaps i simply just feel that way. it makes me wonder if my grad program is unnecessarily harsh on me or if my undergrad program was very easy on me. i'm rather worried that the professors are regretting their decision to admit me and i somehow misrepresented myself. it's very stressful. i feel stupid and yet back home everyone thinks i am some kind of genius for being accepted where I am. i have spoken to two professors and will be talking to another. but is this a sign that grad school isn't for me? because i feel the opposite. this is the only field i want to be in and i am extremely excited over what i will be potentially doing. any advice?