Sorry to hear about your tough situation. I just read through these posts and I think you made the right decision.

My brother did the same thing to my mom last year- moved into her house with his 4 year old son. My poor mother, who is the nicest person on the planet and has the hardest time saying "no," aged more in that one year than she has in the last 5. My nephew, while he is smart and cute and a great little guy, can wear a person out in 10 minutes. Luckily, my brother has moved on and she decided if ever he wants to live with her again, she will just say have to say no for her own sanity.