Nut slapping incident ny DM

This situation happened about two weeks ago. I was working with the DM of the client company making a call on a very difficult doctor. The doctor is known to be tremendously hard to talk to. I did my very best and I thought I made some progress. The DM and I left his office and as we were in the parking lot walking to my car and she was walking next to me she suddenly back handed me in the groin area with fairly significant force. She started telling me the things I should have done differently on the call. I was in considerable pain from where she slapped me but I did my best to hide it. She never said she was sorry or that it was an accident.



My question is; I have been humiliated over this and my wife is very upset. Should I contact our Human resources department or the clients or should I contact an attorney? I found this to be the most unprofessional conduct in my 7 year career. Please submit any helpful advice.

Nut slapping incident ny DM