GF cheated again..am depressed, lost, how to get back to life..?

at several occasions i found out she was cheating on me, i forgive coz i loved her so much, she is financially weak and i supported her a lot with money, car, many many things. Now yesturday i found out she has a seperate mob num.I came to know and i got shocked, she say she hide from me sorry, she cried a lot.i said am leaving you.She said i will never leave u, i cant live without you.i love you so much.she is chasing me like hell, 100 sms calls..she is asking me come back...am so weak at heart i need to cut everything..but heart still beats for her...how to forget someone....please anyone help me...i cannot die like this