You aren’t “living in sin” in the sense of being in an invalid marriage. However, direct sterilization is sinful. It needs to be confessed and absolution sought to return yourselves to a state of grace (unless you have already done so, as C_K indicated). If you consented to it, then you both need to. If you wife did this against your wishes, it is hers to bring to her Confessor.
I think that this is one of those categories, like abortion or birth control, that needs to be confessed, even if you weren’t completely familiar with Church teaching at the time. As adults, there is a certain level of “should have known” that we are responsible for. In any case, take it to Confession and submit yourself to the priest.