I think the line in the first verse "think of bright lights, a splendid feast" is about Christmas and coming home for that time of year. The seething beast is a metaphor, mostly likely for the suburbs, where Siouxsie grew up and felt she didn't belong, hence why she's feeling low as she goes to her literal home.
The second verse suggests that she doesn't go home often, so everything has changed and it's even less than a home than it was before she left the first time.
The chorus basically centres around her desire to go to her real home, which is where she belongs and not the home she was raised in.
I think the line in the first verse "think of bright lights, a splendid feast" is about Christmas and coming home for that time of year. The seething beast is a metaphor, mostly likely for the suburbs, where Siouxsie grew up and felt she didn't belong, hence why she's feeling low as she goes to her literal home.
The second verse suggests that she doesn't go home often, so everything has changed and it's even less than a home than it was before she left the first time.
The chorus basically centres around her desire to go to her real home, which is where she belongs and not the home she was raised in.