I'm about at my wits' end here

This is part rant, part plea for help and suggestions.

Tigerlilly has been using the corner of the dining room as a litter box. It was bad enough when there was a pile of stuff there that we hadn't gotten around to putting away when we moved in. But we cleaned that out and she stopped for while. But lately she's taken to peeing on the bare floor. The wood floor there is pretty much ruined now. I've just put up a blockade from old baby gate stuff, but I fear it just means she'll pee next to it.

I can think of one solution, but DH wants something more humane. As for me, I've gotten so sick of her bad habits that I wouldn't mind never seeing her again.

What happened to me? I used to love cats. These days, I find our two cats to be much greater nuisances than they're worth. I find myself contemplating their ages and wondering how much longer we'll have to put up with them. Maybe it has something to with having kids now, and a huge shift in my priorities.