I don’t think you need the second comma in the second line. It is indeed very dark. The shortening sentences, increased pace all working up to that last, repeated line. Lots of very interesting techniques going on in there and some very interesting little phrases (like the title) that can be picked out as almost beautiful.
The protagonist is pushing reality away in defense so as not to face the horrible screaming mother. That’s what I read, anyway, and that is a terrible thing. But extremely well described.