Keep a roof over our head's

I hate  to ask for help but I don't know what else to do...The house we live in belongs to my best friend, he and my step mother put down $ 60,000.00 to buy it like 9 years ago at $325,000.00 it was valued at $550.000.00 at the time and due to their ages they were given a 9.75 inst  rate..My best friend is almost 80, my step mother died and i am tried to keep him and my grand-kids i am raising in our home. ( my 12 year old is very vary sick issues from birth) I have been working with the bank and have a bank who will forgive the instrest and drop it down to a little over 3% that is what we have been begging them for for over a year now...I need at their bank by 12/31/2018 a check for $3,901.07 on top of my loan payment of $ 1,589.00 ..If not I am in default and they foreclose leaving us all home less... I can make these payments but I just don't have the down payment for all the stuff that it covers...I don't ask anyone for help ever...I help everyone I can even when its all I have I still help people...I have NO family to help me...this is it my one and only attempt to keep a roof over our heads...If you can help in any small way I would appericate it... this is very time limited I have to have this money and send it to the bank by bank wire by the 31st of this month PLEASE PLEASE HELP IF YOU CAN