boyfriend of 6 months now he is my ex broke up w/ me in June. Everything was great at first he said he love me but in june he broke up why?

why would he break up with me? the first few months he told me that he loved me. we met each other family and he introduced me to his friends. he wrote a song for me that talks about how much he loves me. he will always surprise me with gifts and we will joke and have a good time. sometimes we will argue a lil but we will get over it. I told him how much i love him and i didn't want it to end. he said that he likes me as a friend and no matter what he will always be a true and geniue friend to me. he said he is going to miss me and my family but HE SAID HE IS NOT READY FOR COMMITMENT. HOW COULD HE LOVE ME SO MUCH AND THEN NOW DON'T WANT TO BE WITH ME ANYMORE. I CRIED AND BEGGED HIM TO STAY HE WIPPED MY TEARS. I told him that since we will not be together anymore we can still be best friends because we have so much in common he said yes i have no problem with that we can be best friends. I invited him to a concert and he was flirting with me the entire time. now I LOOKED ON HIS SNAP CHAT HE WAS DRIVING AND LISTENING TO A LOVE SONG TALKING ABOUT HOW MUCH HE WILL BE THERE FOR HIS GIRL. & on his other social media he put 1 picture of him with another girl saying that that is his homie and a few weeks ago he put up a video of him dancing with 2 random girls in the club. he knows that im jealous but he still likes my pics that i put up. so now for 2 weeks i havent said nothing to him, im just giving him his space and maybe that would make him miss me