You have some painful decisions to make.
You must give priority to hubby+yourself first.
Let them auction the house - as it now in the name of hubby's sister.
Stop dealing with any of the relatives in financial matters.
Dont worry about hubby's reputation - the truth will surface sooner or later.
If you feel guilty about kicking them - as you say - dont be.There a lot of people you can help.
Free yourself.
Jesus is in you.Follow Him. He is talking to you through hubby
Blessings