I really need help

Ok..her is my problem..i've been bestfriends with this girl 4 amost 4 years now ..and she goes to a different university so i dont get to see her much at all..but shes the only true friend i have..i call her all the time and she does the same.........we'll the bottom line is ((we're close..more than anyone can imagain)
soo what is the problem???...well she is a(super achiever) ..she studies All the time and that makes me very proud of her..i dont care if she didnt call me b/c shez studying or whatever....but these dayz i cant take it anymore ...yesterday we were suppose to go out 4 an hour or so and she cancelled on me before more than once ...so she called and cancelled(AGAIN) ..so i couldnt take it anymore and i didnt wanna fight also so i just told her that i have 2 close to phone now...so she got really upset and said i dont understand what shez goin through and all that
all i wanted was to see her 4 a while..i just dont undersatnad how can an hour ruin her future!!!!!!
so i'm i a horrible friend or what?

u r not a horrible friend! ur friend might just have alot on their mind. talk to ur friend and get them to tell u wats wrong cause u might be able to help her get through watever is wrong. i have already been through similar situations alot in the last few years in school.