to end or not to end

i’ve been with my boyfriend for three years, and we love each other very much, but we’ve both changed so much in the last three years, considering we met when i was a freshman in high school and i’m currently a sophomore in college. i love him with all of my heart, he’s loyal, truthful, genuine, loving. he will be a fantastic husband and father one day. but we seem to have nothing in common anymore. it scares me so badly. and sometimes i’m not very happy in the relationship. but god i love him. so basically, i don’t know what to do. i don’t know if i would be happier if we broke up, and i’m terrified to make a mistake that i can’t take back, because he is so incredibly amazing. we just would argue pretty often and it got to the point (about a month ago) where we took a break for a week and then broke up for a day now i’m feeling like i don’t make him happy even though he says he’s happy. we’re both discouraged and we don’t know what we want anymore, but we for sure both want each other to be happy. any advice?