i'm going thru some relationship issues

i know everyone will tell me to get over it.... but i'm really hurt by this cheating liar. i gave my whole heart to him for the second time and he tore it into tiny pieces, pissed on it, kicked dirt on it and laughed. he swears that he's not cheating... he swears that we aren't broken up... he wants me to come back home so we can work some things out... but i don't want to. how am i supposed to believe him when he runs around at all hrs of the night and then some random female from his myspace tells me that she's his girlfriend and that i need to get over him...???? he's the one still calling me and telling me he still loves me. WTF?!?!?!? i'm so confused!!