Breaking up is hard to do

Don't feel like calling my gf anymore, as we always end up in disputes. It's something about personality clash, something to do also with family upbringing that has caused all those indifferences, friends were saying that couple do argue in order to improve their relationship, but is there a benchmark for me to abide by?Friends also said that it's such a long relationship, so if I let go it would go wasted. There is no benchmark for that, as if the flaws of the relationship are getting more and more prominent till a level that one is unable to tolerate any longer, then something has to be done after a dragging period so as not to waste each other's time any more.