I have some sympathy for the position you are in, but the fact is, if you hit someone, whether it is "just a slap" or a punch, there are likely to be consequences. I don't know what possible scenario could result from the episode you describe, but in the absence of injury to the victim of your assault, and also the absence of a witness to what exactly took place in the room, it might be difficult for her to prove her charge. As far as your work is concerned, it is likely that your reputation will precede you for a while after this, but it will eventually be forgotten.