I broke up with my boyfriend of 8 months in hopes that he would realiz what he was losing & i caved after 2dy?

i found out he was talking to an ex and it broke my heart i told him it was not okay for him to be talking to her after he said he wouldnt since then it was almost like he resented me for it has been acting shaddy so friday we had a fight and i couldnt take anymore i said this is misrible lets just end it so he got all his stuff and left i didnt want it to be over i tought he would of texted or called and nothing so last nite i caved and texted him a sad face he texted back with ??? we texted for a few he basicaly told me he's a loser a quitter and to move on ... what do i do ???