Promissary Note Repayment

[Weedsav8]

What is the name of your state (only U.S. law)? FLORIDA

I made a huge mistake, which of course i did not realize at the time. Me and my soon to be Ex-wife were both signators on a promissary note with her Father for money he lent to us while we were married. Her father offered to lend us money so we could get a house which was a little outside our current budget at the time. Long story short- we became separated, sold the house and i gave the money from the sale of the house to my Ex to pay her father. The total amount of the note is 93,000- 79,000 was the principal loan amount, the remainder is a result of the 5.56% interest rate applied to the principal on the promissary note.
My Ex-wife did not pay her father, and instead paid off her own debt, and then used the rest as she saw fit. Now her father is suing us both- but actually just me. My Ex is in California and has been for some time. Her father was able to track me down and sue me because i am in the Military. I have custody of our children, and have ever since the divorce.
Do i have any chance of making her liable for the 60,000 she spent on her stuff?!! And what will the Head of Household protection due for me in the State of Florida? I take home appx 80,000/yr- should i be expecting to lose some of my paycheck? Or will i be able to essentially avoid paying anything while the kids are in the house?? I'm also looking at filing Bankruptcy is i get a total judgement against me for the full amount- appx 94K. My Ex only makes about 200/mth, but make get married soon to a guy who makes a good living.
Bottom line- how much protection will HOH afford me and my children? Do i have a good chance of suing my Ex for the judgement- i.e., the 60K she spent?

Concerned Single Dad