Needing to become a prisoner in one's own home is a sad state of things. Perhaps relocating to a safer place is in order. There is being aware, being prepared and then there is being paranoid and living in a constant state of fear. I refuse to succumb to the latter.

Simple things besides a dog - thorny bushes like roses or berries under each window. A simple walkway path of small pebbles around the house - try to walk quietly on those, it can't be done. If you're that worried about your front door, the old steel bar across it from inside attached to brackets in the walls does the trick.