Aged Widow and daughter

My mom passed away two years ago from an enlarged heart and clotting in her legs that eventually moved.

Since then my dad (64 years and a pensioner) and younger sister(15 years old and in high school) have been living in the house alone that they have had for more then 5 years.

He tries to do the odd job to pay for his bond, also to take care of himself and my sister and as his daughter I try to help them as much as I can.

Due to old age and the fact that my dad lost his brother, mom and wife and then brother all in one year, mentally he is struggling to cope. Mentally the stress is staring to take a toll on him.

But now we have received a letter from the bank saying that due to the passing of my mom my dad can either sell the house or refinance it by applying for a loan or he has 12 months to settle the house.

If he sells the house to find a smaller place her wont find anything for the amount that he is paying on the bond.

I really need help to settle his bond so that this isn't something that we have to be scared of and financially have to struggle so much.

I'm really desperate.