The estate would be responsible for the debt(not you). Some assets in estate may be exempt from the debt and creditor claims are ranked in different classes. You would need an attorney to sort this out.
"Estate" is a term that is often misused. As prior posts indicated, some of your father's assets might not be subject to probate at all because they were owned in a way that allowed for survivorship rights or beneficiary designations. Such assets would not be part of the "probate estate". Still other assets might be exempt from creditor claims under Florida probate law. In addition, probate expenses and fees are paid before creditors.
Probate acts like bankruptcy in many ways because it provides an orderly process to determine how much is available to pay creditors. Creditors must follow strict rules for filing claims. Florida law determines which creditors should be paid first and how the estate assets are divided among creditors if there are not enough assets to pay everyone.
Florida law also provides that a personal representative is a "fiduciary" and has a duty to pay creditors who have filed valid claims.
I'm unsure how you would be sued personally for your father's debt. If you did not sign a promissory note or other document promissing to pay the loan, the attorney filing the lawsuit might be mistaken. I have seen this in foreclosure actions recently.
If a lawsuit has been filed against you, it is crucial that you contact an attorney immediately because you have a limited amount of time to respond. The attorney you contact should be familiar with the type of lawsuit being filed against you and probate law so that you receive complete advice.
My comments are not intended to establish an attorney-client relationship, are not confidential, and are not intended to constitute legal advice. Proper legal advice can only be given by an attorney who agrees to represent you, who reviews the facts of your specific case, who does not have a conflict of interest preventing the representation, and who is licensed as an attorney in the state where the law applies.