I completely understand, I haven’t ever lived alone, going from parents to flat shares, to husband and children. My husband doesn’t go away as much now, but I always hate it, I leave a landing light on, and am constantly up and down checking the house.
If I lived alone, I would either need a lot of security, or I would need to move.
It’s irrational, because my husband’s days of tackling burglars are probably over, if I hear a noise, it’s me who gets up checking everything, and even one little grandchild makes me feel happier
I think it’s just the fact of being alone. We used to live opposite a nursing home and it was always comforting to look out at night and see lights on, and know someone was up, but it’s just been sold for a chiropractors practice, I can’t imagine they will be there all night!
So sorry, no advice, but you’re definitely not alone with your worries.