I am being charged with harassment, what do I do?

I have filed charges on my soon to be ex husband for harassment and we are awaiting trial. 2 days ago I received a citation in the mail from the magistrate stating that I am harassing him. I have not contacted him since I filed charges against him, over a month ago. He has no evidence of me harassing him, how was he able to file charges? He also states that I falsified information on our custody paperwork, which I did not. I need to know where to go from here. Obviously I will be pleading not guilty but I just don’t understand how he can get all of these charges pressed with no evidence.