it took my family/friends 5 yrs to get to like my boyfriend
Anyway, from what she said, it seems she felt you didn't give her enough attention.
Ive been in a relationship long enough to have found, if you feel you have nothing to to talk about, you argue and sometimes argue about things that don't even matter, (and sometimes forget what you're arguing about) ... Maybe y'all had these little spats (which are healthy for a relationship actually) and she always run to her friends... Making them not like you much?
There has to be something you did (that she grew tired of) or must have just been a lame bf? (and drove her off)
Anyway, you are young and surely there are plenty other girls out there you can meet... Who knows, one day you'll find the right one
(I only read OP first comment so I'd there's something I missed... My bad) anyhow, you should not dwell If you are hurt by the break up, just go out with the guys and have fun. Over time, you will get over her... On and off relationships will do no good