​Being sued

I have a previous landscaping client (artificial turf in florida) that long story short is one of those “nightmare from hell clients” we did work for her and she never signed our contract but we carried on with the work under good faith (my fault)

Then middle of the project she asks for us to do additional things that i oblige to because i try to work with people and maintain our 5stars. Low and behold shes dangling the final payment over our head while asking if we things that were never talked about or agreed on- which we do so we can just get paid and leave.

2 weeks later she calls and asks why something wasnt done that was never talked about listed in estimate or anything (an item amounting to about 1500$ labor undoing something and adding something new) i tell her that theres nothing we can do because it wasnt included- she starts screaming and swearing i try to work with her and say if she pays for a portion of it we’ll come and do it under good faith. Hangs up and then calls again a few days later listing 10 new unreasonable complaints (“it just doesnt look professional, im unhappy” we do amazing work and have never had one customer like this over hundreds) . At this point ive reached my limit and say i dont think it would be a good idea for us to work together anymore.

Recieved a letter from her attourney yesterday who called me and used lots of curse words “you guys did a sh- job and if i have to be an ahol- then ill be one and you guys fu- up” (yes this is a real lawyer from a real firm) which i didnt respond to anything and said ill email my attorney info. Im a 20Y Male so this is new territory for me.

Looked up the customers info- aparently has a bad legal history lots of unpaid tickets, child endangerment, and tried suing someone she got in an accident with (same lawyer) to the tune of over 100k but case was dismissed before it was even heard.

Tried contacting lots of attourneys but nobody really answered (labor day wknd.) or had like a free consult- were small im not made of money and would like to handle this without breaking the bank as im still in college.

Edit: just so everyone knows this client paid the estimate amount through quickbooks shouldve been north of 20k but i only charged barley over 10k and walked away with less than 750$ profit (which clearly states in the estimate what our scope is) but is now conducting this behavior