You need to learn how to forgive yourself first. Do you think a minor detail like that would have been something that would have convinced your partner to leave you? It sounds like you two worked everything out and built up that trust again. Bringing it up now only serves to clear your own conscience at the cost of opening up old wounds.
Look, you acknowledge that you made a mistake, you’ve atoned for the bad things that you’ve done and made amends with your partner, and you’ve found a blissful happiness. It’s time to let that baggage go and forget the past. It won’t be easy, but the first step is to realize that everybody is fallible and that sometimes we make mistakes and we can’t always rely on having our guilt absolved by another.