If the cop saw you it is unlikely you can fight it unless you have evidence to the contrary.
I agree with trying to negotiate it to a lesser offense so you don't lose your license.
A local attorney who is experienced with traffic matters should be able to assist. It is too serious to go into court without representation.
Almost anything can be negotiated. You definitely should plead not guilty and request a hearing to give yourself a chance. The fact that you have a clean driving record will help in the negotiations. However, I too believe you should get a local attorney to help fight for you. He or she may know the officer or District Justice which can only help.