Depressed state

How do you know when enough is enough?  How can you decide that you can no longer manage this person whom you love at home? This has been a particularly trying weekend and by the end of it I am a spent force physically, emotionally and just about every other which way. I berate myself and say " Surely you can do better than this?" but I am not so sure. His moments of clariy are becoming so few and the anxiety and endless questioning almost unbearable. Today we had a problem with something in the house. He would just go to the hotel desk and get them to fix it. Don't I wish.