Hi Peter A
I'm guessing it must have been a big blow to you in some ways, having to move back into your parents/losing your home, I'm sorry

And it does sound like it may feel pretty overwhelming at times with your parents, niece, sister and the dog there along with the "ugliness" of the clutter?? I have seen your name in the autism forum so maybe that has an impact on how you're experiencing your current situation in those respects??
But you mentioned being in supported accomodation before...........could maybe you or your parents push Social Services to find you a support provider who can support you in finding a private tenancy somewhere?? That's if you haven't tried that already!!
For now though could it be aspects of your living situation or just a general feeling that relates to the depression??
Just wondering whether you could find some coping skills e.g. grounding exercises or distractions if it's aspects of your living situation triggering and worsening the feelings inc. of anxiety??
Just some thoughts............
Alison