I cheated on my wife and am sorry and now I want her back, but don't know how to win her back?

It was 9 years ago that I cheated...but I've lied about it all the way until she discovered the truth last month. I also was stupid and contacted my ex via phone/email 3 years ago. I never met her in person and I cut off communication, but my wife knows about that too...I want to win her back, but I dont know what to do...everything I try she says isnt real and not good enough...please help...any suggestions