I need urgent legal help with a demand letter sent by attorney of a tenant who used to rent my house through a property management company

I have received a demand letter from attorney for the tenant that used to live at my property located at 1415 Regents Ln, Apex, NC. They have threatened litigation if I do not settle in the amount of 50,000 to 60,000 dollars. I believe the demand is not frivolous and highly unreasonable. I have a whole timeline of events and communications documented. I also have all the documents ready. I want to hire a lawyer to respond to the demand letter and fight the case if the other side goes for further litigations.