Your date of separation is September 2016 not May.
In NJ there is what is called bright line rule that says absent a formal separation agreement, the date of separation is the date that the divorce is filed with the court. There are some (very few) exception but none of them have to do with sexual relations.
See Painter v. Painter, 320 A. 2d 484 - NJ: Supreme Court 1974
You have already filed, why do you think you need to file again? In NJ , you do not need to be separated for any period of time to file for divorce. The divorce laws have changed. In fact, you can live under the same roof and still file for a no-fault divorce.After this event in May 2016 we did not see each other again and have since filed for divorce in september 2016.
The date of separation is only going to effect the equitable distribution of marital assets and debts.

