From your wife's standpoint, I can tell you, the hardest thing right now is living with the fact that you have been lying to her for so long. It's the lying that is hardest to take. You say to yourself that you lied to protect her, but really you lied to protect yourself from her (rightful) reaction to your behavior.
Now - what I have to say here may sound tough, but - you need to come clean with everything now. Totally clean. You may be telling yourself "I can't tell my wife X or Z because it will hurt her and she might leave me" - but the truth is, you are only trying to protect yourself. The truth ALWAYS comes out eventually, and if you are still lying about ANYTHING, she will not be able to stick around when it comes out later.
Is it risky to tell her the whole truth right now? Sure, it is - I won't lie to you. But it is way riskier for her to find something out later - and believe me, it always comes out.
What exactly am I getting at? Well, Zuki, I've been here for 3 years now, and my gut instinct tells me that the odds that this affair remained an emotional affair and never progressed to a physical affair are slim to none. So - if you ever did sleep with the OW, or had oral sex, or whatever - now's the time to fess up, get tested for STDs, and take your lumps.
