By the way, when Protection Order got expired? Before submitting I-129F or later?
Lying to US govt. officials is a very serious offense which could bar for life to avail any benefit. In my personal opinion, your choices are as follow-
(1) Hire an attorney quickly and respond to it before the due date. Trust me, attorneys know how to get over this kinds of situation. They will easily be able to establish that it wasn’t a deliberate lie on your part, rather a mistake/misunderstanding. I know many people will debate this over here until its eternity but trust me attorneys know well how to handle this kinds of things. So long you can able to prove/establish that you didn’t lie deliberately on this, you are ok.
(2) You can let it deny this petition now, and then file another one with truthful information. I don’t think any immigration petition is denied with prejudice, rather they are all denied without prejudice...What it meant is- you are free to re-apply again. And yes, US govt. keep all the record of your previous filings, but each application/petition is dealt on its on merit. Govt. can not deny your next petition/application based on the information contained on previous petitions because then burden will lie solely upon them to prove that you intentionally and deliberately lied to them. Merely having something on the application/petition can’t be construed as if you lied to them deliberately. People make many mistakes all the time, knowingly or unknowingly...sometime typo and other times because of their failure in not understanding a question properly. I think you will be ok, trust me.
(3) You should get married and apply for CR-1 visa. You can even marry thru zoom now without leaving your living room...