Tell us once system does not work

my husband died in February and I followed the tell us once, two weeks ago I received a Phone call informing me that I was in aarrrears with my rent and since my husband was deceased I needed to pay fulll rent. 
I am awaiting my benefits claims to be sorted and visited the uncan Center for some support the lady was helpful and told the housing officer that I was waiting a decision on my benefits.. on Friday I reciievd a visit from the housing officer with two letters one for me and one for my late husband  both letters adressed to both of us, in them was. A notice to quit my property.  I was a carer for my husband and my brother at the same time, I feel so distressed and wanted to end it all I don’t know what to do.