I subscribe to the 'you wont pick it up, I'll chuck it in the bin' school of thought. My mom did it to me, I learned my lesson,and I've done it to Jordan, now she's nice and tidy. Didn't damage anyone, but instiled accountability. Dont pick it up, but then be responsible for going WITHOUT!
You are NOBODY'S housemaid, time to set some very clear boundaries, but only you can decide what those will be... So sorry you've got so much on your plate, its time to clear some of that off there