I am currently doing the same thing with my Aby Tama. He's been having quite a few problems which a few people here know about, but anyway, my last resort was to get a cage for him.

He has his blanket, catnip toy, food, water, and litterbox in there. I thought when I first put him in there that he would freak out crying and trying to get out but he loves it in there! Whenever I'm home I leave the cage door open for him to roam the house but he rarely comes out. When he does come out, sometimes he'll just perch himself on top of the cage.

Since he's been in there, he has stopped pooping and urinating on the floor. He is a spite pooper, I've been dealing with that for his entire life..sigh.

I still can't believe how much he likes it in there. When I come by to see him, he just purrs.

I think that maybe he likes it so much because to him, it's his 'safe spot'. Kinda like his own little room.

I'm sure it looks like I'm being mean to the cat, but it has solved a few problems (he's still got a LOT of problems I can't seem to fix) and he seems to not mind it, so I'm fine with it.