Noa, 31, said Friday in a pretrial hearing that he regrets agreeing to a June 30 preliminary injunction that prohibits him from "criticizing, denigrating, casting in a negative light or otherwise disparaging or causing disparagement" to Lopez.
"I want to fight this thing to the end," he said. "My life has not been the same since this lawsuit was filed."
The judge gave Noa until Jan. 17 to hire a lawyer or represent himself.
Lopez filed her lawsuit April 10 and obtained a temporary restraining order barring Noa from publishing intimate details of their sex life.
Noa said Friday that Lopez misunderstood what the book was about.
"This was to be about my life story, coming here from Cuba," he said. "She was only a part of my life, but I was going to talk about my other girlfriends, as well."
Lopez, who has appeared in films such as "Selena" and "Out of Sight," married Noa in February 1997 after meeting him in a Miami restaurant. They divorced 11 months later.