I dumped my boyfriend! it feels really bad :-( !! help please!!?

i dumped my ex cause i realized i made a wrong choice! (though he proposed me) .. it was just not working out. And then i moved out of our city for higher studies n distance added to the problems... now after 3 months of dumping him.. i have fallen for someone else...bt my ex still loves me.. i dont wanna move back but i feel very very guilty now...to hurt someone so much.. i feel depressed!!! please help me get over it!!