Is that possible to vacate everything but the actual divorce??
In a word, NO.
However, if certain affirmative steps were required to finalize your divorce, you might not be divorced.
I suggest you contact the county clerk where the divorce was filed and attempt to secure yourself a final decree.
FL has very good "sunshine laws".
You might be able to check for yourself by searching the applicable county website.
As far as the rest of the "deadbeat's" babbling, stop talking to him.
He's probably been lying, hoodwinking, and bamboozling your for years.
Would you actually take your time and listen to the devil?
Stop listening to a lying, sack of rotten potatoes, masquerading as a deadbeat father.
Now if he's remarried without benefit of a legal divorce, you might want to talk to a detective or district attorney investigator.
Why?
He may be committing BIGAMY, or he may just be spouting more lies.
He'll owe child support until the day he dies.
There's no way the Florida is going to sign off on a deadbeat evading or avoiding child support.
Collecting it may be another issue, but if he ever hit the lottery, you could get paid!!!
Don't even discuss letting that weasel screw you and your kid anymore.
Custody ain't gonna happen either, for him.
Good luck.