my mother passed away and she had a cc i was told i did not have to pay her debt. but they called me 1 mo. after death and said i was responsible

they threatened me me that they would take the house and every I owned if I did not sign an agreement with them.. soo out of fear I did, and now they put a lien on my name , house. credit score b/c I had stopped paying them b/c I cannot afford to pay what they are asking and when I said to lower it ( still out of fear they would kick me and my kids out on the street ) they said no. and now they put it in the courts.... they have ruined my credit score and I am scared... please help