[FL] Father is suing me because I won't give him any of my money

I [21F] am from FL.

The title of this post pretty much sums everything up.

My dad wants to sue me because I refuse to give him any of the money I'm getting in a lawsuit. He says that I "owe him for all the expenses he spent on my when I was younger" and that I should do this because I'm his daughter and he is an old man who needs to survive. My parents are not married and they are not together and have not been together for quite sometime. I'm adding this in here that I am also the only person over my own financial information and I have no qualms with my mother stealing money from me (even though when I was younger, I saved up over $160.00 from when my mom would pay me for doing chores in the house and getting good grades and when my father was staying with us, he stole that money from me, promising to give it back and never did).

I got into an accident about 6 months ago and I'm getting a pretty large settlement. I haven't disclosed the potential number to anyone but my mother, but due to where it happened and the extent of my injury and the recovery period, my father and other family members are pretty much being opportunist and trying to help me out throughout the whole thing because they're looking for handouts and I know this for a fact (so does my mom and she's the ONLY person I trust in our family). I have a great aunt who keeps complaining that her retirement funds are getting low and that she needs someone to give her some money to help out because she's old, but that's for r/relationship_advice

Anyway, I told him that I was not obligated to give him anything at all and that if he's only trying to be in my life for that reason, he needs to leave me alone.

Haven't heard from him in over two weeks until yesterday I get a letter from a random law firm saying I'm being sued for causing him [Father] distress and some other bullshit. A totally different subject matter, but he's always tried stuff like this:

1. Attempting to get both myself and brother's SSNs so he could use them to get credit cards, open businesses, etc
2. File us on his taxes even though he was not living with us or taking care of us at all.

I'm new to this whole legal area and I need to know what my options are regarding the lawsuit he's giving me and legally what can I do to get him to stop harassing me for monetary gains?