There are presumably all sorts of valuable things you need in the house? Documents, as well as personal belongings?
Can you go to CAB or a solicitor tomorrow? or would Women's Aid advise you?
After double checking with CAB or a solicitor, I would take my name off all the bills you are currently paying, from today's date.
If you can get into the house - maybe with SIL's help - take everything that could be of use: Children's birth certificates, all your bank and finace details , yours and childern's passports, and everything that proves you made payments on the mortgage.