Disclaimer: This is in NO way to be construed as an "excuse" for your asinine choice in April.
IC, until you are able to accept that you are HUMAN -- and are able to be (to a reasonable degree) both accepting and forgiving of your own f*ckups (sexual or otherwise) AND put in place sensible safeguards to lessen the possibility of them occuring in the first place per SG's advice -- you will not be a good partner.
Remorse, regret, desire to amend ... all good. But the perpetual and extravagant welding of a hairshirt to your carcass is not. It's no more balanced or fun to live with that than a guy who would do the opposite: blow something like this off completely and/or blame his wife.
Don't you dare put Miss IC in the position of trying to stuff her anger and feel *sorry* for you because you've melted down into a little puddle of guilt. It's ultimately a selfish emotion.
You are not Superman. You never were. Trying to be superhuman is a fool's game and always will be.
((((Miss IC)))) -- this sucks.
Saffie has it right ... there are no guarantees, and also I agree with SG: it could happen to anyone, given the right circumstances. Again, totally not excusing it .... but IC is no more uniquely flawed than he is uniquely unflawed.
You are the only one who can decide what you can live with. My only advice is to do nothing in haste.
My best to you both.
"Show me a completely smooth operation and I'll show you someone who's covering mistakes. Real boats rock." -- Frank Herbert