Is what happened to me – being touched and kissed by a coworker, despite my resistance but inner consent – considered zina (fornication/adultery) that necessitates the hadd punishment? Are all my good deeds invalidated? Have I become forbidden to my husband? And how can I repent and return to the obedience of Allah Almighty?

You must repent to Allah Almighty for what has occurred, and repentance wipes away sins. You must conceal what happened and not inform anyone about it, leave the work that causes you to mix with the man, and avoid approaching him. What you have fallen into does not necessitate a hadd punishment or stoning, nor does it make you forbidden to your husband, nor does it nullify your deeds. Your duty is to repent and increase in acts of obedience.