Landlord lawsuit

[keeth31]

I needed to terminate my lease 4 months early. I gave my landlord 60 days notice. He is holding 3.5 months worth of security deposit. The building is not rent stabilized or controlled.

According to my lease I am responsible for any advertising fees to re-rent the apartment. My landlord said he would advertise and pass the cost on to me. He waited until 30 days prior to my proposed move out date before he advertised the apartment. He also decided to sell the apartment instead of renting it.

I was late paying my rent in April because I was asking him to use my security deposit. I eventually did pay. Two weeks after I paid the bill I got a summons that my landlord is suing me for $6000. The rent is only $1850 and it is fully paid up.

My questions are:
1. What should I do about the lawsuit
2. Could I counter sue to get my security back since the landlord did not use best efforts to lessen my damages.

Any help is appreciated.