unpaid credit card from a closed bank

i had a credit card from Solid Bank when i was single. The bill was more than 30K. When i got married i had to stop working to take care of our soon to be born child. My husband can only support us just enough since we just got married. i never had a job since and when Metrobank absorbed the old bank i paid 3K but told them i couldn't pay any longer since i dont have a job and is expecting a child. Now i'm getting letters from a law firm telling me to pay unsttled accounts amounting to almost 900K. What should i do?? i still dont have enough money to pay? i have three kids going to school, i cannot sacrifice their education for the bills? will i be in trouble for a 30K unpaid card?? HELP pls