My insurance will not pay for my car that was totaled in a accident

I was at hospital in Chattanooga with my brother when his girlfriend just had to go home I ask my friend to take her home in my car and I would bring my brother home in his car when his pacemaker was put in. My friend was not on my policy because they had always told me that she just had to have my permission. She rents a room from me at my house and Allstate told me they changed their policy and you have to have them on your policy now since January of this year I did not receive this notice, I still had the old insurance card in my auto at the time of the wreck. I had full coverage on my autos and house for thirty to forty years with them Allstate is now trying to get my brother to hire their lawyer to sue me for his girlfriend being hurt I need help